5U+  Sr 
?i£* 


author’s  abstract  of  this  paper  issued 

BY  THE  BIBLIOGRAPHIC  SERVICE,  JUNE  2.7 


Reprinted  from  The  Journal  of  Comparative 
Neurology,  Vol.  33,  No.  3,  August,  1921 


THE  LIBRARY 
OF  THE 


’M 

«  .  k»  «  I* 

ON  THE  GROWTH  OF  THE  LARGEST  NERVE  CELLS  IN 
THE  SUPERIOR  CERVICAL  SYMPATHETIC  GAN¬ 
GLION  OF  THE  ALBINO  RAT— FROM  BIRTH  TO 
MATURITY 

CHI  PING 

The  Wistar  Institute  of  Anatomy 

•  " 

SIX  CHARTS  AND  ONE  PLATE 

INTRODUCTION 

This  paper  contains  observations  on  the  largest  nerve  cells  in 
the  superior  cervical  sympathetic  ganglion  of  the  albino  rat. 
The  purpose  of  this  study  is  to  trace  the  growth  of  these  cells 
by  their  increase  in  diameter  in  relation  to  the  age  and  size  of 
the  animal.  In  order  to  compare  the  possible  differences  in 
growth  in  the  sympathetic  nerve  cells  due  to  sex,  a  male  and  a 
female  rat  of  each  age  were  used  throughout  the  series  of 
observations. 

The  author  desires  to  express  his  sincere  appreciation  and 
gratitude  to  Dr.  M.  J.  Greenman  for  granting  him  the  privileges 
and  facilities  of  the  Institute  for  this  investigation,  and  to  Dr. 
H.  H.  Donaldson,  under  whose  direction  the  work  was  carried  on 
and  whose  valuable  advice  and  guidance  enabled  him  to  formu¬ 
late  his  results. 

MATERIAL 

The  material  used  for  this  investigation  consisted  of  sixteen 
pairs  of  albino  rats,  of  known  ages,  from  1  to  365  days.  Besides 
these,  two  females  of  540  days  and  570  days,  respectively,  were 
used  for  comparison.  All  these  were  obtained  from  the  animal 
colony  at  The  Wistar  Institute  and  belonged  to  the  so-called 
'standard  strain.’  In  selecting  the  specimens,  five-day  intervals 
were  taken  between  each  two  ages  from  birth  to  thirty  days, 
but  from  this  age  onward  greater  intervals  were  used.  The 
body  weight,  body  length,  sex,  and  age  of  each  rat  were  recorded. 

281 


282 


CHI  PING 


For  comparison  and  control  a  second  limited  series  of  inbred 
albino  rats  was  also  used.  The  data  for  this  series  are  given  on 
page  303.  Up  to  the  introduction  of  this  series  the  paper  deals 
only  with  albino  rats  of  the  ‘standard’  strain. 

TECHNIQUE 

The  rat  was  etherized  and,  after  the  necessary  measurements 
had  been  noted,  was  completely  eviscerated.  The  superior 
cervical  sympathetic  ganglion  was  removed  from  each  side.  In 
the  removal  care  was  exercised  to  avoid  distortion  of  the  tissue, 
for  mechanical  injury  to  the  ganglion  is  likely  to  affect  the  size 
and  shape  of  its  cells.  As  the  ganglion  is  small,  it  was  deemed 
necessary  to  remove  it  in  the  mass  of  other  tissues  which  closely 
invest  it. 

Both  ganglia  from  each  rat  were  prepared,  but  only  one  was 
used  for  measurements.  No  distinction  between  right  and  left 
was  made  in  the  record. 

Aiming  at  a  satisfactory  preservation  of  the  natural  size  of  the 
cells,  I  followed  King’s  (TO)  recommendation  of  Bouin’s  solution 
for  fixation.  The  ganglia  from  older  rats  were  fixed  in  the  solu¬ 
tion  for  twenty-four  hours,  while  for  those  from  the  younger 
ones— from  birth  to  twenty-five  days  old— the  period  was  reduced 
to  twelve  hours.  Such  a  reduction  of  the  fixation  period  has 
given  satisfactory  results. 

The  specimen  was  washed  in  different  grades  of  alcohol,  from 
70  to  98  per  cent,  containing  a  small  amount  of  carbonate  of 
lithium.  By  so  doing  the  yellow  tinge  given  to  the  tissue  by  the 
fixation  was  completely  removed.  The  specimen  stayed  in  the 
alcohols  of  lower  grades  for  twelve  or  more  hours,  and  in  the  90 
and  98  per  cent  alcohol  for  about  one  hour.  It  was  finally  trans¬ 
ferred  to  cedar  oil  for  twenty-four  hours  for  complete  dehydra¬ 
tion.  Paraffin  of  52°  was  used  for  imbedding.  By  employing 
an  electric  bulb  above  the  container  the  paraffin  was  kept  melted 
only  in  its  upper  layer  in  the  jar,  the  specimen  sinking  to  the 
contact  line  between  the  melted  and  unmelted  paraffin. 

Under  these  conditions  the  specimen  could  be  left  in  the 
paraffin  for  thorough  penetration  as  long  as  seemed  necessary 
without  danger  of  overheating. 


SYMPATHETIC  CELLS  I  ALBINO  BAT 


283 


Serial  sections  of  the  entire  ganglion  were  cut  8  n  in  thickness. 
Heat  from  an  electric  bulb  was  used  in  flattening  the  sections. 
The  slide  was  placed  underneath  the  bulb,  so  that  the  water  that 
served  to  float  the  sections  on  the  slide,  also  chilled  them  from 
beneath,  when  they  were  spread  by  the  heat. 

The  procedure  in  staining  was  as  follows:  The  sections  were 
passed  from  xylol  down  through  the  graded  alcohols  to  water, 
and  then  put  for  five  minutes  in  a  saturated  solution  of  lithium 
carbonate,  after  which  they  were  stained  for  two  or  three  minutes 
in  a  one-third  saturated  solution  of  thionin.  They  were  then 
passed  up  through  the  graded  alcohols  to  xylol  and  mounted  in 
acid-free  balsam.  So  far  as  possible,  the  plane  of  section  was 
made  perpendicular  to  the  short  axis  of  the  ganglion,  thus  giving 
the  maximum  area. 

MEASUREMENTS  OF  THE  CELLS  AND  NUCLEI 

The  cells  and  nuclei  of  the  ganglion  were  measured  with  an 
eyepiece  micrometer,  using  a  Zeiss  ocular  no.  6,  and  objective, 
4  mm.  Each  division  in  the  micrometer  scale  was  equivalent 
to  4.47  /j.  The  measurements  were  made  in  the  following  way: 
In  the  case  of  each  specimen  a  section  at  the  middle  of  the  series 
was  selected.  Starting  both  ways  from  this,  four  more  sections 
were  selected,  two  in  each  direction,  by  skipping  every  other 
section.  In  this  manner  five  sections  altogether  were  chosen 
and  marked  for  study.  In  each  of  the  five  sections  the  two 
largest  cells  were  measured;  thus  ten  cells  in  all  were  measured 
in  each  ganglion. 

There  were  four  principal  points  kept  in  mind  when  selecting 
the  cells  for  study:  First,  the  cells  must  be  the  largest  in  the 
section;  second,  they  must  be  uninuclear;  third,  the  nucleus 
must  be  located  at  or  near  the  center  of  the  cell  and  must  be 
fairly  large;  fourth,  in  the  nucleus  at  least  one  nucleolus  must  be 
present. 

Under  these  conditions,  the  measurements  made  on  the  cells 
and  nuclei  are  considered  to  represent  the  maximal  longitudinal 
and  transverse  diameters  of  each  cell  and  nucleus  taken  close 
to  their  median  planes.  It  was  often  found  in  this  study  that 


50158 


284 


CHI  PING 


the  boundaries  of  a  cell  body  were  obscure.  Furthermore,  the 
distribution  of  the  Nissl  granules  was  rather  irregular  (as  will 
be  described  later),  so  that  neither  the  longitudinal  nor  the 
transverse  diameter  could  be  measured  according  to  the  extent 
of  the  stainable  mass. 

After  the  measurements  had  been  taken,  a  sketch  of  the  section 
with  the  two  cells  measured  therein  was  made,  and  the  nucleoli 
in  these  cells  were  noted,  so  that  in  making  measurements  for 
the  second  time  the  same  cells  could  be  identified  by  their  location 
and  the  number  of  the  nucleoli.  As  a  matter  of  routine,  the  cells 
in  each  ganglion  were  measured  twice,  a  considerable  time  being 
allowed  to  elapse  between  the  first  and  second  measurements. 
The  procedure  in  measuring  did  not  follow  in  the  order  of  age  or 
of  body  weight  of  the  animal,  as  given  in  the  tables,  but  was 
purposely  haphazard,  and  in  making  measurements  for  the  second 
time,  the  records  were  taken  without  referring  to  those  already 
made.  The  values  used  are  the  means  of  the  two  series. 

By  this  procedure  prejudice  was  avoided  and  a  more  accurate 
determination  of  the  size  of  the  cells  and  nuclei  obtained.  The 
records  thus  made  were  tabulated  in  detail,  but  the  averages  of 
the  values  for  the  ten  cells  in  each  ganglion  are  those  used  for 
the  tables,  charts,  and  discussion  which  follow.  The  individual 
data  have  been  filed  in  the  archives  of  The  Wistar  Institute. 

The  square  roots  of  the  products  of  the  longitudinal  and  trans¬ 
verse  diameters  of  the  cells  and  of  the  nuclei,  respectively,  for 
each  ganglion  were  averaged,  and  the  mean  was  multiplied  by 
4.47,  the  value  in  of  one  division  of  the  eyepiece  scale.  In 
table  1  the  diameters  of  the  cells  and  nuclei  thus  computed  are 
arranged  according  to  age,  and  in  table  2  according  to  the  body 
weight  of  the  animal. 

Based  on  the  records  in  tables  1  and  2,  charts  1  and  2  were 
plotted.  Chart  1  shows  on  age  the  graphs  for  the  diameter  of  the 
cells  and  nuclei  in  micra  and  chart  2  the  same  relations  on  body 
weight. 

In  the  graphs  for  the  cells  in  chart  1  we  see  in  the  increase 
before  puberty  only  chance  variations  between  the  male  and  the 
female  in  diameter  of  the  cell  body,  but  after  the  rat  has  attained 


SYMPATHETIC  CELLS:  ALBINO  RAT 


285 


the  age  of  eighty  days  (body  weight  about  100  grams)  which  is 
the  period  of  puberty  (Donaldson,  ’15,  The  Rat,  p.  21)  there 
appears  a  tendency  for  the  cells  to  be  larger  in  the  female  than 
in  the  male.  It  will  be  noted,  however,  that  at  the  age  of  eighty- 
nine  days,  and  also  at  250  days,  the  male  exhibits  larger  cells  than 
the  female  of  the  same  age.  This  discrepancy  is  explained  when 
we  take  the  body  weights  of  the  males  into  consideration.  As 
given  in  table  1,  the  body  weight  of  the  male  rat  eighty-nine  days 
old  is  twice  that  of  the  female  of  the  same  age,  and  the  dis¬ 
crepancy  is  even  greater  in  the  case  of  the  male  at  250  days. 

These  males  should  be  expected  to  have  larger  nerve  cells  by 
virtue  of  their  body  weight,  and  when  a  correction  is  made  for  it, 
the  values  for  the  male  cells  should  fall  below  those  for  the  female 
at  these  ages  also.  In  general  one  may  say  that  the  female, 
after  reaching  puberty,  has  these  cells  larger  than  the  male,  if 
the  body  weight  of  the  male  does  not  too  greatly  exceed  that  of 
the  female.  As  regards  the  nucleus,  however,  chart  1  exhibits 
a  less  clearly  marked  sex  difference. 

The  fact  that  there  is  a  better  growth  of  the  cell  bodies  in  the 
female  is  more  clearly  illustrated  in  chart  2,  in  which  graphs  for 
the  diameters  of  the  cells  and  nuclei  have  been  plotted  on  body 
weight.  From  birth  to  the  time  just  before  puberty,  the  varia¬ 
tions  in  the  growth  of  these  cells  in  the  two  sexes  are  similar  to 
those  shown  in  chart  1. 

Just  before  puberty,  when  the  rat  weighs  about  60  grams,  the 
female  becomes  gradually  more  advanced  in  the  growth  of  these 
cells  and  overtakes  the  male  of  the  same  body  weight.  The 
growth  of  the  nerve  cells  in  the  female  also  shows  a  more  regular 
course  than  that  of  the  male.  The  growth  of  the  nuclei  at  the 
corresponding  ages  of  the  two  sexes  follows  in  the  same  manner 
as  that  of  the  ceil  bodies,  although  the  difference  is  relatively 
small. 

9 

It  is  proper  to  keep  in  mind,  however,  that  when  the  compari¬ 
son  is  made  on  the  basis  of  body  weight,  the  female  is  normally 
the  older,  and,  further,  that  in  several  other  growth  changes  the 
female  tends  to  be  precocious;  both  of  these  influences  would 
tend  to  produce  larger  cells  in  the  female  under  these  conditions. 


286 


CHI  PING 


TABLE  1 


Computed  diameters  of  the  largest  cells  and  nuclei  according  to  age.  From  the 
superior  cervical  sympathetic  ganglion  of  the  albino  rat 


A 

B 

c 

D 

E 

p 

SEX 

AGE 

BODY 

WEIGHT 

BODY 

LENGTH 

Computed  diameter  in  y 

RATIO  OF 
DIAMETER  OF 
NUCLEUS  TO 

Cell 

Nucleus 

DIAMETER  OF  CELL 

days 

grams 

mm. 

cf 

1 

5.6 

50 

19.5 

11.4 

1:1.72 

$ 

1 

6.3 

51 

19.8 

10.2 

1:1.93 

cf 

5 

9.0 

63 

22.1 

10.7 

1:2.06 

$ 

5 

11.0 

65 

21.3 

10.5 

1:2.03 

cf 

11 

15.0 

77 

24.9 

13.1 

1:1.90 

$ 

ii 

14.0 

73 

26.4 

13.1 

1:2.02 

cf 

16 

18.9 

83 

25.3 

13.1 

1:1.92 

9 

16 

19.0 

81 

23.1 

11.2 

1:2.06 

cf 

20 

31.7 

102 

26.4 

12.5 

1:2.11 

9 

20 

29.5 

99 

23.6 

11.8 

1:1.99 

cf 

25 

23.8 

93 

26.6 

12.6 

1:2.11 

9 

25 

25.5 

95 

27.3 

12.7 

1:2.15 

cf 

29 

40.7 

112 

27.1 

12.0 

1:2.26 

9 

29 

16.4 

82 

24.8 

12.2 

1:2.03 

cf 

42 

61.4 

129 

27.0 

13.4 

1:2.01 

9 

42 

43.5 

105 

27.2 

13.2 

1:2.05 

cf 

48 

105.1 

156 

29.0 

13.4 

1:2.17 

9 

48 

49.7 

120 

27.0 

13.1 

1:2.05 

cf 

60 

51.6 

124 

27.2 

13.2 

1:2.06 

9 

62 

53.8 

117 

27.1 

13.1 

1:2.07 

cf 

81 

63.3 

128 

27.4 

13.3 

1:2.06 

9 

80 

83.7 

142 

26.6 

12.8 

1:2.09 

.cf 

89 

143.5 

173 

32.4 

13.0 

1:2.49 

9 

88 

73.0 

135 

29.2 

13.2 

1:2.21 

cf 

124 

151.1 

174 

27.1 

13.0 

1:2.08 

9 

124 

107.1 

157 

30.5 

13.8 

l:-2.21 

cf 

171 

198.2 

192 

27.0 

13.1 

1:2.05 

9 

171 

123.8 

159 

30.9 

12.8 

1:2.41 

cf 

250 

230.0 

207 

36.8 

15.4 

1:2.38 

9 

250 

98.0 

160 

30.6  . 

14.2 

1:2.15  • 

cf 

365 

186.0 

203 

29.6 

•  13.5 

1:2.20 

9 

365 

170.6 

186 

31.4 

13.5 

1:2.31 

9 

540 

151.3 

184 

30.7 

13.4 

1:2.29 

9 

570 

127.1 

169 

33.4 

14.3 

1:2.34 

SYMPATHETIC  CELLS:  ALBINO  RAT  287 

On  examining  the  ratios  between  the  values  at  one  day  and  at 
365  days,  as  shown  in  columns  D  and  E  of  table  1,  it  is  found  that 
the  cells  in  the  male  have  increased  in  diameter  1.55  times,  and 
in  the  female  1.58  times,  while  the  nuclei  in  the  male  have  increased 
1.17  times  and  in  the  female  1.32  times.  This  shows  that 
the  difference  between  the  male  and  female  in  the  growth  of  the 
nuclei  in  the  course  of  one  year  is  greater  than  that  in  growth 
of  the  cells,  but  the  cells  in  both  sexes  have  a  greater  rate  of 
growth  than  do  the  nuclei,  as  indicated  in  table  1. 


Chart  1.  Based  on  table  1  and  giving  the  computed  diameters  of  the  cells 

and  their  nuclei  according  to  sex — on  age  in  days.  Males - 

Females - 

The  graphs  in  chart  1  show  that  the  increase  in  the  diameter 
of  the  cell  body  is  rapid  for  the  first  twenty-five  days  and  then 
becomes  slower.  There  is  a  similar  change  in  the  nucleus,  though 
the  change  in  the  rate  of  growth  in  this  case  is  less  marked.  From 
25  to  365  days  the  diameters  of  the  cells  and  of  the  nuclei  of  the 
two  sexes,  have  increased  as  shown  in  table  3. 

In  column  F  of  table  1  are  given  the  ratios  between  the  diameter 
of  the  cell  body  and  that  of  the  nucleus.  Generally  speaking, 
the  cell  has  about  twice  the  diameter  of  the  nucleus  throughout 
the  series  of  measurements  as  given  in  table  1,  but  if  we  consider 
the  ratios  carefully,  we  see  that  there  is  an  increase  in  the  ratios 


288 


CHI  PING 


TABLE  2 


Computed  diameters  of  the  largest  cells  and  nuclei — on  body  weight — together  with 
the  nucleus  plasma  ratios — from  the  superior  cervical  sympathetic 

ganglion  of  the  albino  rat 


SEX 

A 

AGE 

B 

BODY 

WEIGHT 

c 

BODY 

LENGTH 

D 

E 

F 

NUCLEUS  PLASMA 
RATIOS 

Computed  diameter  in  ju 

Cell 

Nucleus 

days 

grams 

mm. 

d 

1 

5.6 

50 

19.5 

11.4 

1:  4.0 

$ 

1 

6.3 

51 

19.8 

10.2 

1:  6.3 

d 

5 

9.0 

63 

22.1 

10.7 

1:  7.8 

9 

5 

11.0 

65 

21.3 

9  10.5 

1:  7.3 

9  • 

11 

14.0 

73 

26.4 

13.1 

1:  7.2 

d 

11 

15.0 

77 

24.9 

13.1 

1:  5.8 

9 

29 

16.4 

82 

24.8 

12.2 

1:  6.8 

d 

16 

18.9 

83 

25.3 

13.1 

1:  6.2 

9 

16 

19.0 

81 

23.1 

11.2 

1:  7.7 

d 

25 

23.8 

93 

26.6 

12.6 

1:  8.4 

9 

25 

25.5 

95 

27.3 

12.7 

1:  8.9 

9 

20 

29.5 

99 

23.6 

11.8 

1:  7.0 

d 

20 

31.7 

102 

26.4 

12.5 

1:  8.0 

d 

29 

40.7 

112 

27.1 

12.0 

1:10.5 

9 

42 

43.5 

105 

27.2 

13.2 

1:  7.7 

9 

48 

49.7 

120 

27.0 

13.1 

1:  7.7 

d 

60 

51.6 

124 

27.2 

13.2 

1:  7.7 

9 

62 

53.8 

117 

27.1 

13.1 

1:  7.8 

d 

42 

61.4 

129 

27.0 

13.4 

1:  7.2 

d 

81 

63.3 

128 

27.4 

13.3 

1:  7.5 

9 

88 

73.0 

135 

29.2 

13.2 

1:  9.8 

9 

80 

83.7 

142 

26.6 

12.8 

1:  7.9 

9 

250 

98.0 

160 

30.6 

14.2 

1:  9.0 

d 

48 

105.1 

156 

29.0 

13.4 

1:  9.1 

9 

124 

107.1 

157 

30.5 

13.8 

1:  9.8 

9 

171 

123.8 

159 

30.9 

12.8 

1:13.1 

9 

570 

127.1 

169 

33.4 

14.3 

1:11.7 

d 

89 

143.5 

173 

32.4 

13.0 

1:14.4 

d 

124 

151.1 

174 

27.1 

13.0 

o 

00 

T— I 

9 

540 

151.3 

184 

30.7 

13.4 

1:11.0 

9 

365 

170.6 

186 

31.4 

13.5 

1:11.6 

d 

365 

186.0 

203 

29.6 

13.5 

1:  9.5 

d 

171 

198.2 

192 

27.0 

13.1 

1:  7.7 

d 

250 

230.0 

207 

36.8 

15.4 

1:12.6 

SYMPATHETIC  CELLS  I  ALBINO  RAT 


289 


as  age  advances,  as  they  are,  respectively,  1  : 1.72  and  1  : 1.93 
for  the  youngest  male  and  female;  1  :  2.11  and  1  :  2.15  at  twenty- 
five  days,  and  1  : 2.34  for  the  oldest  female. 

This  increase  is  therefore  most  marked  during  the  first  twenty- 
five  days.  By  comparing  the  progress  from  birth  to  twenty-five 
days  with  that  from  twenty-nine  days  to  365  days,  one  can 
appreciate  the  rapid  increase  in  amount  of  cytoplasm  within  the 
former  period,  as  contrasted  with  the  slower  increase  in  the  course 


Diameters  of  Cells  and  Nuclei  in  micra 

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Body  weight— gms. 

I 

- 1 

tit  mil' 

40 


30 


20 


10 


25 


50 


75 


100 


i  25 


150 


175 


200 


250 


Chart  2  Based  on  table  2  and  giving  the  computed  diameters  of  the  cells 

and  their  nuclei  according  to  sex — on  body  weight.  Males - 

Females - 


of  a  much  longer  time.  It  is  fair  to  say,  therefore,  that  the  ratios 
change  but  slowly  after  the  first  twenty-five  days.  This  agrees 
with  the  statement  of  Donaldson  and  Nagasaka  (T8)  on  the 
ventral  horn  cells,  that  after  twenty-four  days  the  nucleus- 
plasma  ratio  increases  but  slowly. 

VARIABILITY  WITHIN  A  GIVEN  GANGLION 

The  number  of  large  cells  examined  in  each  ganglion  is  hardly 
great  enough  to  permit  of  satisfactory  statistical  treatment, 
but  it  has  been  thought  worth  while  to  tabulate  for  each  animal 
the  range  and  average  of  the  diameters  of  the  cells  and  of  the 


290 


CHI  PING 


nuclei,  entering  these  according  to  age  as  in  table  1.  In  a  fairly 
graded  series  of  measurements  we  may  expect  to  find  the  average 
for  the  series  close  to  the  mean  of  the  limiting  values,  and  a  little 
study  of  table  4  shows  this  to  be  the  case. 

MORPHOLOGY  OF  THE  LARGE  CELLS 
Plate  1.  (Figures  1  to  7) 

In  considering  the  morphology  of  the  cells  in  the  superior 
cervical  sympathetic  ganglion,  it  must  be  recalled  that  from  its 
cells  arise  several  classes  of  fibers — pupillodilator  fibers,  motor, 
vasomotor,  pilomotor  and  secretory  fibers.  It  is  a  priori  possible, 


TABLE  3 

Increase  in  diameters  of  cells  and  nuclei  from  25  to  365  days 


GAIN 

DIAMETERS 

SEX 

25  DAYS 

365  DAYS 

Absolute 

Percentage 

M 

U 

Cells . | 

d' 

26.59 

27.26 

29.60 

31.38 

3.01 

11.3 

15.1 

$ 

4.12 

Nuclei . | 

cf 

12.60 

13.45 

0.85 

6.31 

9 

12.65 

13.54 

0.89 

6.58 

that  the  several  functions  thus  indicated  are  correlated  with  cell 
characters  that  are  distinctive,  but  at  the  moment  we  have 
nothing  to  contribute  to  the  solution  of  this  problem. 

When  young,  the  cells  of  the  superior  cervical  ganglion  are 
very  similar  in  appearance  to  those  of  the  young  spinal  ganglion, 
and  practically  all  of  them  are  more  or  less  elongated  with 
processes  at  one  or  both  ends.  Each  cell  has  a  large  clear  nucleus 
surrounded  by  a  little  cytoplasm.  This  cytoplasm  is  homogene¬ 
ous  in  structure  and  stains  uniformly.  Those  coarse  Nissl 
bodies,  which  are  found  in  the  cells  at  later  ages,  are  totally  lacking. 
Usually  each  nucleus  has  a  single,  dark  stained,  nucleolus,  but 
occasionally  there  may  be  found  more  than  one.  This  condition 
continues  from  birth  to  five  or  six  days  of  age,  when  differentia¬ 
tion  begins  in  the  cytoplasm  of  these  immature  cells. 


SYMPATHETIC  CELLS:  ALBINO  RAT 


291 


TABLE  4 


Giving  the  ranges  in  the  values  for  the  diameters  of  the  largest  cells  and  their  nuclei 
in  the  superior  cervical  sympathetic  ganglion  of  the  albino  rat — 
arranged  according  to  sex  and  age 


SEX 

AGE 

BODY 

WEIGHT 

CELLS 

NUCLEI 

Diameter 

Range 

Diameter 

Range 

days 

grams 

M 

M 

M 

U 

d1 

1 

5.6 

19.5 

22.0-18.0 

11.4 

14.0-  9.4 

$ 

1 

6.3 

19.8 

24.0-17.4 

10.2 

12.0-  9.4 

c? 

5 

9.0 

22.1 

25.0-20.0 

10.7 

14.0-  9.0 

$ 

5 

11.0 

21.3 

25.0-18.3 

10.5 

12.3-  9.0 

9 

11 

14.0 

26.4 

30.0-23.0 

13.1 

15.0-11.0 

d1 

11 

15.0 

24.9 

30.4-22.0 

13.1 

13.7-11.6 

d 

16 

18.9 

25.3 

29.0-22.0 

13.1 

14.0-12.0 

9 

16 

19.0 

23.1 

25.0-20.3 

11.2 

14.0-10.0 

9 

20 

295.0 

23.6 

27.0-19.4 

11.8 

16.0-10.4 

d1 

20 

317.0 

26.4 

29.0-24.0 

12.5 

14.0-11.0 

d 

25 

238.0 

26.6 

31.0-23.0 

12.6 

14.0-11.0 

9 

•  25  ' 

25.5 

27.3 

31.0-24.7 

12.7 

14.0-11.0 

9 

29 

16.4 

24.8 

26.0-22.7 

12.2 

14.0-  9.4 

d 

29 

40.7 

27.1 

30.0-24.7 

12.0 

14.0-10.0 

9 

42 

43.5 

27.2 

31.0-24.7 

13.2 

16.0-11.0 

d 

42 

61.4 

27.0 

30.0-24.7 

13.4 

16.0-12.0 

9 

48 

49.7 

27.0 

29.0-24.7 

13.1 

15.0-  9.0 

d 

48 

105.1 

29.0 

33.0-26.4 

13.4 

15.0-12.6 

d 

60 

51.6 

27.2 

30.0-24.0 

13.2 

15.0-12.4 

9 

62 

53.8 

27.1 

30.0-24.0 

13.1 

15.0-11.6 

9 

80 

83.7 

26.6 

29.0-25.7 

12.8 

13.7-11.6 

d 

81 

63.3 

27.4 

31.5-25.7 

13.3 

15.6-11.0 

9 

88 

73.0 

29.2 

31.0-26.0 

13.2 

14.6-11.0 

d 

89 

143.5 

32.4 

36.7-28.5 

13.0 

14.6-11.0 

9 

124 

107.0 

30.5 

33.0-29.0 

13.8 

16.0-13.0 

d 

124 

151.1 

27.1 

28.5-25.0 

13.0 

14.0-11.7 

9 

171 

123.8 

30.9 

33.7-29.0 

12.8 

13.7-  9.7 

d 

171 

198.2 

27.0 

32.4-24.7 

13.1 

14.0-12.4 

9 

250 

98.0 

30.6 

33.0-26.6 

14.2 

16.0-14.0 

d 

250 

230.0 

36.8 

39.0-35.6 

15.4 

18.0-14.4 

9 

365 

170.6 

31.4 

38.0-28.5 

13.5 

15.6-12.3 

d 

365 

186.0 

29.6 

33.7-26.6 

13.5 

16.0-12.0 

9 

540 

151.3 

30.7 

34.4-28.3 

13.4 

14.7-11.0 

9 

570 

127.1 

33.4 

36.7-29.0 

14.3 

16.0-14.0 

292 


CHI  PING 


At  birth  or  during  the  first  days  of  life  there  are  found  among 
the  young  cells  a  few  advanced  cells  which  appear  conspicuously 
different  from  the  rest.  In  these  advanced  cells  the  cytoplasm 
may  be  already  differentiated,  even  at  birth.  The  stainable 
Nissl  granules,  which  are  of  course  much  finer  than  those  found 
at  later  ages,  are  evenly  but  distinctly  distributed  through  the 
entire  contents  of  the  cell.  Among  these  granules  some  clear 
spaces  appear  which  seem  to  indicate  the  differentiation  of  the 
homogeneous  cytoplasmic  mass,  and  this  change  in  the  advanced 
cells  must  have  commenced  during  fetal  life. 

When  the  young  cells  begin  to  develop,  there  is  the  same  dif¬ 
ferentiation  of  the  cytoplasmic  mass,  and  the  stainable  bodies 
arrange  themselves  in  the  same  way  as  those  seen  in  the  advanced 
cells.  Hereafter  more  differentaition  will  be  found  in  them  and 
the}^  grow  to  resemble  the  advanced  cells  in  appearance. 

Taking  this  as  the  starting-point  in  the  morphological  develop¬ 
ment,  we  see  among  the  comparatively  large  cells  in  the  ganglion 
four  types  which  probably  appear  one  after  the  other  as  here 
given  in  the  course  of  growth. 

Type  1.  The  advanced  cells  and  the  cells  which  are  trans¬ 
forming  into  advanced  cells,  as  described  above,  belong  to  this 
type.  There  is  a  beginning  of  aggregation  of  the  Nissl  granules 
and  a  growth  of  the  unstainable  ground-substance  in  the  cells. 
This  type  is  common  during  the  first  twenty  days  of  postnatal 
life  (fig.  2). 

Type  2.  The  Nissl  bodies  are  larger  than  in  type  1  and 
aggregated  at  the  periphery  of  the  cells,  forming  a  ring  within 
which  is  a  comparatively  clear  portion  of  the  ground-substance 
surrounding  the  nucleus.  The  Nissl  bodies  stain  much  darker 
than  in  type  1.  The  nuclear  membrane,  the  nucleoli,  and  the 
reticular  structure  in  the  nucleus  are  distinctly  visible.  There 
are  frequently  two  or  more  nucleoli  in  one  nucleus.  This  type 
is  common  in  the  period  between  twenty  and  sixty  days  (fig.  3), 
but  may  also  be  found  at  birth  (fig.  1). 

Type  3.  Instead  of  being  distributed  at  the  periphery,  the 
Nissl  bodies  are  aggregated  around  the  nucleus,  leaving  a  rather 
clear  space  at  the  periphery  of  the  cell.  In  some  of  the  cells  they 


SYMPATHETIC  CELLS!  ALBINO  RAT 


293 


are  more  crowded  at  certain  regions  close  to  the  nucleus,  forming 
dark  masses,  but  some  of  them  may  be  loosely  scattered  toward 
the  periphery.  It  is  in  this  type  of  cell  that  difficulties  have 
often  been  encountered  in  making  out  the  boundary  between 
the  cell  wall  and  the  supporting  tissue,  because  the  unstained 
ground-substance  is  chiefly  distributed  at  the  periphery  of  the 
cell.  This  type  is  common  after  twenty  days  of  age,  but  is  not 
infrequently  found  after  sixty  days  (fig.  4). 

Type  4.  The  cells  resemble  the  first  type  in  the  arrangement 
of  Nissl  bodies,  but  the  stainable  bodies  are  much  coarser.  There 
is  a  considerable  evenness  in  their  distribution,  though  here  and 
there  we.  find  a  larger  dark  stainable  mass  resulting  from  their 
aggregation.  Whether  this  type  is  developed  from  the  preceding 
type  through  modifications  in  the  course  of  development  or 
whether  it  is  directly  derived  from  type  1,  without  undergoing 
the  various  changes  as  in  types  2  and  3,  is  a  matter  to  be  settled 
through  more  detailed  investigation  (fig.  5).  This  type  is 
characterized  by  the  dense  appearance  of  Nissl  bodies  throughout 
the  entire  cell  body,  not  leaving  much  space  for  the  ground- 
substance,  and  is  common  at  the  age  of  124  days  and  later. 

In  interpreting  these  several  types  it  is  to  be  recalled  that 
the  cells  of  this  ganglion  have  several  different  functions  and 
there  always  remains  the  possibility  of  a  correlation  between 
function  and  morphology. 

Besides  the  four  types  of  cells  described  above,  binuclear  cells 
are  found  at  all  ages  until  the  rat  is  very  old.  In  recording 
them,  special  care  needs  to  be  taken.  As  the  cell  wall  of  the 
sympathetic  cell  is  at  times  difficult  to  distinguish,  two  uninuclear 
cells  in  close  contract  with  each  other  may  frequently  resemble 
one  cell  with  two  nuclei.  In  order  to  avoid  error  due  to  such 
misleading  appearances,  the  precaution  has  been  taken  to  use  an 
oil-immersion  lens  in  distinguishing  the  true  binuclear  cells 
from  those  which  resemble  them.  The  cells  which  have  their 
cytoplasm  discontinuous  somewhere  between  the  nuclei  or  a 
constriction  at  the  middle,  either  slight  or  pronounced,  as  the 
one  figured  by  Apolant  (’96,  Majer’s  ‘cell  bridge/  fig.  8,  pi. 
XXIII),  were  not  considered  as  of  the  true  binuclear  type. 


294 


CHI  PING 


TABLE  5 


Giving  the  number  of  the  cells  with  two  nuclei  and  of  the  cells  showing  pigment,  at 
different  ages.  Superior  cervical  sympathetic  ganglion — albino  rat. 

In  each  case  the  numbers  are  for  one  ganglion  only 


SEX 

AGE 

BODY  WEIGHT 

BODY  LENGTH 

NUMBER  OF  BI- 
NUCLEAR  CELLS 

CELLS  WITH 

PIGMENT 

cf 

days 

1 

grams 

5.6 

mm. 

50 

2 

0 

9 

1 

6.3 

51 

2 

0 

cf 

5 

9.0 

63 

1 

0 

$ 

5 

11.0 

65 

2 

0 

cf 

11 

15.0 

77 

1 

0 

9 

11 

14.0 

73 

2 

0 

cf 

16 

18.9 

83 

1 

0 

9  . 

16 

19.0 

81 

1 

0 

cf 

20 

31.7 

102 

2 

0 

9 

20 

29.5 

99 

4 

0 

cf 

25 

23.8 

93 

4 

0 

9 

25 

25.5 

95 

3 

0 

cf 

29 

40.7 

112 

3 

0 

9 

29 

16.4 

.  82 

3 

0 

cf 

42 

61.4 

129 

5 

0 

9 

42 

43.5 

105 

12 

0 

cf 

48 

105.1 

156 

4 

0 

9 

48 

49.7 

120 

2 

0 

cf 

60 

51.6 

124 

5 

0 

9 

62 

53.8 

117 

5 

0 

cf 

81 

63.3 

128 

3 

0 

9 

80 

83.7 

142 

12 

0 

cf 

89 

143.5 

173 

7 

0 

9 

88 

73.0 

135 

1 

1 

cf 

124 

151.1 

174 

15 

8 

9 

124 

107.1 

157 

6 

0 

cf 

171 

198.2 

192 

2 

4 

9 

171 

123.8 

159 

9 

0 

cf 

250 

230.0 

207 

4 

0 

9 

250 

98.0 

160 

5 

3 

cf 

365 

186.0 

203 

6 

3 

9 

365 

170.6 

186 

4 

2 

9 

540 

151.3 

184 

2 

4 

9 

570 

127.1 

169 

3 

13 

Average  of  binu clear  cells: 


SYMPATHETIC  CELLS:  ALBINO  RAT 


295 


Every  one  of  the  cells  recorded  in  table  5  had  an  unbroken  layer 
of  Nissl  granules  around  the  two  nuclei,  and  at  the  middle  of  the 
cell  there  existed  absolutely  no  trace  of  any  partition  whatsoever 
which  might  suggest  the  contiguous  surfaces  of  two  cells  closely 
grown  together.  Figures  6  and  7  show  the  binuclear  cells  in  a 
very  young  and  in  a  comparatively  old  rat,  respectively. 

If  we  determine,  by  direct  measurement,  the  nucleus-plasma 
relation  in  this  particular  older  cell  (fig.  7),  contrasting  the  volume 
of  both  nuclei  with  that  of  the  cytoplasm,  we  find  a  ratio  of 
1  :  5.0.  This  is  almost  as  low  as  the  ratio  at  birth,  and  indicates 
that  we  are  dealing  with  an  increase  in  the  nuclear  mass  not 
accompanied  by  a  corresponding  increase  in  the  cytoplasm. 
This,  so  far  as  it  goes,  is  an  argument  against  the  suggestion  that 
we  have  here  two  cells  that  are  fused. 

According  to  table  5,  the  occurrence  of  binuclear  cells  is  not 
related  to  sex.  In  many  cases  the  numbers  of  these  cells  in  both 
sexes  are  equal  or  almost  equal.  There  appears,  however,  to  be 
an  increase  in  their  number  toward  middle  age,  ranging  from 
sixty  days  to  365  days,  with  a  possible  decrease  later. 

Apolant  found  cells  of  the  binuclear  type  in  the  superior 
cervical  ganglion  of  an  embryo  rabbit  three  weeks  old,  and 
states  that  such  cells  persist  in  the  older  animal,  when  the  cells 
have  been  completed  anatomically  and  physiologically.  Accord¬ 
ing  to  him,  this  is  the  result  of  direct  nuclear  division ;  about  half 
of  the  binuclear  cells  being  formed  during  embryonic  life  and 
the  remainder  later.  It  is  not  the  purpose  of  this  paper  to  deal 
with  the  function  and  origin  of  this  type  of  cells.  Their  appear¬ 
ance  in  the  postnatal  stages  of  the  rat,  as  recorded  in  table  5, 
agrees  with  what  Apolant  points  out  as  the  course  of  the  develop¬ 
ment  of  the  cells  in  the  later  ages  of  the  animal.  Carpenter  and 
Conel  (T4)  noted  this  type  of  cells  in  considerable  number  in  the 
rabbit,  guinea-pig,  muskrat,  and  porcupine,  but  rarely,  if  ever, 
did  they  find  them  in  the  sympathetic  ganglion  of  the  rat. 

As  these  authors’  observations  were  made  most  probably  on 
one  or  on  only  a  few  stages  of  the  rat,  the  small  number  of  such 
cells  in  the  entire  ganglion  justifies  their  statement,  in  a  way  but 
nevertheless  the  presence  of  the  binuclear  cells  in  the  superior 
cervical  sympathetic  of  the  rat  is  beyond  question. 


296 


CHI  PING 


Incidentally,  pigmented  cells  have  been  noted  in  the  superior 
sympathetic  ganglion  of  the  albino  rat.  The  cells  of  compara¬ 
tively  young  animals,  from  birth  to  eighty  days,  are  entirely 
free  from  pigment.  At  the  beginning  of  puberty  we  occasionally 
find  pigment  in  one  or  two  cells  in  an  entire  ganglion.  The 
number  of  the  pigmented  cells  tends  to  increase  as  age  advances, 
as  recorded  in  table  5.  Some  of  the  cells  are  only  partly  pig¬ 
mented;  a  few  are  completely  covered  with  these  granules,  the 
nucleus  remaining  unaffected,  while  others  are  totally  pigmented, 
including  the  nucleus.  The  pigments  appear  yellow  brown,  or, 
black  in  color,  but  whether  this  is  merely  a  result  of  their  relative 
abundance  or  whether  there  are  several  sorts  of  pigment  has  not 
been  determined.  The  whole  question  of  pigment  in  the  Albino 
nervous  system  seems  worthy  of  a  special  investigation. 

INCREASE  IN  THE  NUMBER  OF  THE  LARGE  CELLS 

The  increase  in  the  number  of  the  large  cells  in  the  ganglion 
during  the  first  twenty  days  is  an  important  event.  This  is 
chiefly  due  to  the  rapid  increase  in  diameter  of  the  young  cells 
after  ten  or  fifteen  days  of  age.  The  large  cells  measure  19  to 
25  ijl  in  diameter,  and  are  loosely  scattered  and  intermingled 
with  small  cells,  as  seen  in  each  section.  Disregarding  their 
finer  differences,  such  a  group  of  cells  consists  of  three  kinds: 

1.  The  advanced  cells.  During  embryonic  development  it  is 
known  that  the  sympathetic  trunks  are  formed  through  the 
migration  of  some  cells  which  pass  from  the  spinal  cord  along  the 
paths  of  the  communicating  rami  (Kuntz,  TO).  The  advanced 
cells  in  the  superior  cervical  ganglion  are  the  forerunners  of  the 
neurones  which  come  to  this  locality  in  “  skirmish  order — much 
in  advance  of  the  others ”  and  “they  represent  but  a  fraction  of 
the  final  number  of  large  cells”  (Donaldson,  T7).  The  number 
of  these  cells  during  the  first  twenty  days  varies  from  one  to 
eight  in  the  entire  ganglion. 

2.  The  moderately  large  cells.  These  cells  constitute  an 
intermediate  group  between  the  advanced  cells  and  the  small 
cells  in  the  same  ganglion  during  the  first  ten  days  of  age.  They 
are  not  different  from  other  younger  cells  in  general  structure  and 


SYMPATHETIC  CELLS!  ALBINO  RAT 


297 


TABLE  6 

Increase  in  number  of  large  and  advanced  cells,  19  to  25  u  in  diameter,  during  the 
first  twenty  days  of  life.  The  ratios  in  the  increase  in  the  total  number  for  both 
sexes  between  one  day  and  twenty  days  stand  at  the  foot  of  the  column.  Superior 
cervical  sympathetic  ganglion — albino  rat 


SEX 

AGE 

BODY  WEIGHT 

NUMBER  OF  LARGE 
CELLS  AND  OF 
ADVANCED  CELLS 

days 

grams 

cf 

1 

5.6 

188 

$ 

1 

6.3 

174 

& 

5 

9.0 

289 

9 

5 

11.0 

306 

cf 

11 

15.0 

291 

9 

11 

14.0 

301 

'  cF 

16 

18.9 

760 

9 

16 

19.0 

584 

cF 

20 

31.7 

2508 

9 

20 

29.5 

2248 

Ratios:  j 

'<?  13.34 

9  12.91 

Chart  3  Based  on  table  6  and  showing  the  number  of  large  cells  present  in 
the  superior  cervical  sympathetic  ganglion  of  the  albino  rat  from  birth  to  twenty 
days  of  age.  Males - .  Females - . 


298 


CHI  PING 


form,  but  they  are  distinguishable,  owing  to  their  larger  size. 
It  is  this  group  of  cells  which  will  appear  later  as  the  advanced 
cells. 

3.  The  growing  small  cells.  These  cells  are  small  during  the 
first  five  days  after  birth,  but  some  of  them  grow  very  fast  toward 
the  end  of  twenty  days,  to  a  size  equal  to  that  of  the  other  large 
cells.  There  is  a  constant  increase  in  the  number  of  these  smaller 
cells  which  are  growing. 

For  the  determination  of  the  rate  of  increase  in  the  number  of 
the  large  cells,  19  to  25  n  in  diameter,  counting  was  undertaken. 
The  cells  counted  comprised  those  just  described  under  1  and  2. 
Since  the  same  large  cell  does  not  appear  in  two  successive  sec¬ 
tions,  repetition  in  counting  them  is  easily  avoided.  Table  6 
gives  the  numbers  of  these  cells.  Based  upon  these  numbers, 
the  graphs  in  chart  3  were  plotted  on  age.  In  chart  3  the  male 
has  a  slightly  higher  rate  of  increase  than  has  the  female  after 
twelve  days.  When  the  animal  reaches  sixteen  days,  both  sexes 
show  a  more  rapid  increase,  and  the  difference  between  them 
becomes  more  evident.  If  the  data  are  plotted  in  a  like  manner 
on  the  body  weight,  they  show  similar  relations.  On  the  whole, 
then,  the  data  show  that  the  increase  of  large  cells  during  the 
first  sixteen  days  is  relatively  slow  and  afterward  increasingly 
rapid.  Between  the  age  limits  here  given  the  increase  in  the 
number  of  large  cells — sexes  combined — is  about  thirteen-fold. 

THE  TRANSFORMATION  OF  THE  YOUNG  CELLS 

During  the  later  period  of  development  there  remain  in  this 
ganglion  a  number  of  young  cells  which,  in  contrast  with  the 
large  cells,  are  slow  in  growth  and  which  retain  their  neuroblastic 
appearance  for  a  considerable  length  of  time  (fig.  1).  As  already 
noted,  some  nerve  cells  are  precocious  and  many  of  them  have 
attained  their  maximum  size  at  the  end  of  twenty  to  twenty-five 
days.  It  is  most  probable  that  the  young  cells  found  after 
twenty-five  days  of  age  are  largely  rudimentary  elements,  and 
some  of  them  will  never  grow  to  the  same  size  as  the  others. 
Yet  some  development  is  going  on  in  both  their  structure  and 
size,  as  is  indicated  by  the  constant  decrease  of  their  number 


SYMPATHETIC  CELLS  I  ALBINO  RAT 


299 


TABLE  7 


Showing  the  changes  in  the  number  of  young  cells  from  the  period  just  prior  to  puberty 
to  the  end  oj  one  year.  Superior  cervical  sympathetic  ganglion — albino  rat 


SEX 

AGE 

BODY  WEIGHT 

NUMBER  OF  YOUNG 
CELLS 

• 

days 

grams 

d 

60 

51.6 

470 

9 

62 

53.8 

471 

d 

89 

143.5 

362 

9 

88 

73.0 

345 

d 

124 

151.1 

326 

9 

124 

107.1 

252 

d 

171 

198.2 

242 

9 

171 

123.8 

207 

d 

365 

186.0 

105 

9 

365 

170.6 

102 

Ratios: 


1:0.224 

1:0.217 


0  100  150  200  250  300  350  400 


Chart  4  Based  on  table  7.  Showing  the  changes  in  the  number  of  young  cells 
in  the  superior  cervical  sympathetic  ganglion  of  the  albino  rat  between  sixty  and 
365  days  of  age.  Males - .  Females - . 


300 


CHI  PING 


toward  the  end  of  one  year.  A  study  of  the  rate  in  the  decrease 
of  the  young  cells  will  serve  as  a  means  of  measuring  this  change 
at  later  ages.  For  this  purpose  counting  was  undertaken. 
Because  of  their  considerable  number  during  the  early  prepubertal 
stage,  as  well  as  their  small  size  and  irregular  distribution,  it  is 
almost  impossible  to  obtain  a  satisfactory  value  by  a  single 
count,  so  that  a  second  and  a  third  count  were  usually  made. 

The  numbers  recorded  in  table  7  represent  averages  of  three 
counts  of  young  cells  in  each  ganglion.  The  cells,  selected  and 
counted  as  young  cells,  have  the  following  characters:  They 
are  5  to  10  n  in  long  diameter;  more  or  less  pyriform,  and  the 
cytoplasm  is  little  differentiated. 

The  graphs  in  chart  4  represent  the  numbers  of  the  cells  as 
given  in  table  7,  on  age.  The  decrease  in  number  at  first  shows 
no  tendency  for  one  sex  to  outrun  the  other,  but  a  difference 
appears  soon  after  puberty,  and  such  a  difference  in  decrease  of 
the  young  cells  between  the  male  and  the  female  persists  till  the 
end  of  one  year.  The  young  cells  of  the  female  rat  in  relation 
to  age  are  transformed  more  rapidly  than  those  of  the  male; 
that  is,  these  cells  grow  faster  in  the  female.  This  phenomenon 
is  in  accord  with  what  has  been  seen  in  the  growth  of  large  cells 
in  diameter,  as  shown  in  charts  1  and  2. 

DISCUSSION 

There  is  reason  to  think  that  at  birth  the  full  number  of  cells 
in  the  superior  cervical  sympathetic  of  the  albino  rat  has  been 
attained  and  that  no  more  cells  wander  in  and  mitosis  is  finished. 
These  cells  appear  to  persist  throughout  the  span  of  life. 

Postnatal  development  of  these  cells  consists  in  the  enlarge¬ 
ment  of  all  parts  of  the  neuron  accompanied  by  differentiation. 
In  the  nucleus  there  is  less  change  in  size  than  in  the  cell  body. 
The  increase  in  number  of  nucleoli  has  been  frequently  noted, 
but  it  is  not  within  the  scope  of  the  present  paper  to  discuss  this 
point. 

Bringing  the  observations  together,  we  see  that  the  male  and 
the  female  do  not  differ  clearly  from  each  other  in  the  growth  of 
these  nerve  cells  until  the  animal  has  become  sexually  mature. 


SYMPATHETIC  CELLS!  ALBINO  RA'yT 


301 


The  rate  of  increase  in  the  number  of  the  large  cells  in  the 
superior  cervical  ganglion  is,  if  anything,  a  little  lower  in  the 
females  before  twenty  days  and  a  little  higher  later.  On  the 
other  hand,  the  increase  in  size  shows  only  chance  variations 
during  the  first  seventy  days.  These  variations  are  subject  to  the 
influence  of  both  age  and  body  weight  of  the  young  animal,  but 
puberty  is  attained,  sex  begins  to  be  significant  in  addition  to 
the  other  two  factors. 

If  there  is  not  too  much  difference  between  the  ages  and  the 
body  weights  of  the  male  and  of  the  female,  then  the  difference 
found  in  the  quantitative  development  of  the  cytoplasm  between 
the  two  may  be  attributed  to  this  influence  of  sex.  In  table  8 

TABLE  8 


Giving,  according  to  sex,  the  average  computed  diameters  of  the  cell  and  the  nucleus 
for  three  groups  of  body  weights  of  albino  rats.  In  the  last  column  are  given  the 
ratios  between  the  cell  and  the  nucleus  diameters.  Data  condensed  from  table  2 


SEX 

NUMBER  OF 

BODY  WEIGHT 

DIAMETERS 

RATIO  OF 
DIAMETER  OF 

CASi£S 

Cell 

Nucleus 

NUCLEUS  TO  CELL 

c? 

4 

grams 

5.6-  18.9 

M 

22.9 

M 

12.1 

1:1.89 

Q 

5 

6.3-  19.0 

23.1 

11.4 

1:2.03 

d1 

7 

23.8-105.1 

27.2 

12.9 

1:2.11 

9 

9 

25.5-107.0 

27.7 

13.1 

1:2.11 

c? 

5 

143.5-230.0 

30.6 

13.6 

1:2.25 

$ 

4 

123.8-170.6 

31.6 

13.5 

1:2.34 

is  given  a  condensed  statement  of  the  cell  measurements  according 
to  sex,  based  on  body  weights  as  these  appear  in  table  2.  For 
the  cell  body  the  values  are  in  favor  of  the  female  for  all  three 
groups. 

After  puberty  the  sympathetic  neurons  in  the  female  tend  to 
have  larger  cell  bodies  and  the  small  cells  transform  more  rapidly. 

At  the  moment  it  would  not  be  wise  to  infer  that  similar  rela¬ 
tions  would  be  found  in  other  sympathetic  ganglia  or  in  other 
strains  of  rats;  nevertheless,  as  they  stand,  the  results  agree  with 
the  suggestion  of  Dunn  (T2)  that  the  mass  of  the  peripheral 
nervous  system  in  the  female  albino  rat  is  greater  in  proportion 
to  the  body  weight  than  in  the  male. 


302 


CHI  PING 


In  table  9  are  given  the  amounts  by  which  the  cell  diameters 
of  the  females  differ  from  those  for  the  males  at  four  ages  after 
eighty  days.  The  mean  excess  for  the  females  is  about  6.9  per 
cent,  which  represents  approximately  an  excess  of  20  per  cent 
in  volume.  When  a  corresponding  comparison  is  made  for  the 
diameters  of  the  nuclei  in  these  four  groups,  the  average  difference 
according  to  sex  is  feund  to  be  zero. 

TABLE  9 

Showing,  in  jour  age  groups,  the  absolute  and  percentage  difference  in  the  cell 
diameters  of  the  largest  cells  in  the  superior  cervical  sympathetic  ganglion  of  the 
female  albino  rat  as  compared  with  the  male,  based  on  the  values  in  table  1. 
Because  of  the  great  difference  in  the  body  weights,  the  data  for  the  group  at  250 
days  are  omitted 


AGE 

CELL  DIAMETER  IN  THE  FEMALE  DIFFERS  FROM  THAT  IN  THE  MALE  BY 

Absolute  fl 

Percentage 

days 

80 

-0.8 

-  3.0 

124 

+2.6 

+  9.6 

171 

+3.9 

+  14.4 

365 

+  1.8 

+  6.0 

Average . 

+  6.9 

On  the  size  of  these  cells  in  the  inbred  albino  rat 

To  determine  whether  the  size  relations  according  to  sex  which 
have  just  been  described  for  albino  rats  belonging  to  the  so- 
called  1  standard  strain’  are  generally  found,  a  series  of  inbred 
Albinos  was  examined,  for  comparison. 

The  specimens  used  in  this  study  were  furnished  by  Dr.  Helen 
D.  King.  These  rats  had  been  closely  inbred  for  thirty-four  to 
thirty-five  generations.  Seven  pairs  were  used,  ranging  from 
eighty-nine  days  to  154  days  and  each  pair  was  from  the  same 
litter.  The  preparation  of  the  specimens  was  made  in  the  same 
manner  as  that  for  the  series  just  described. 

The  records  on  sex,  age,  body  weight  and  length  and  the 
measurements  of  the  cells  and  nuclei  are  given  in  the  following 
table  10. 


SYMPATHETIC  CELLS!  ALBINO  RAT 


303 


Using  table  10,  chart  5  was  plotted  on  age.  The  graphs  show 
a  slight  difference  in  the  size  of  the  cells  of  the  male  and  female. 
The  male,  as  indicated  by  the  graphs,  seems  to  have  a  better 
growth  in  the  cytoplasm  than  the  female  of  the  same  age,  but 
the  difference  is  small  and  cannot  be  considered  as  primarily 

TABLE  10 


Data  on  the  inbred  albino  rats  from  the  colony  of  Doctor  King.  Diameters  of  largest 
cells  in  the  superior  cervical  sympathetic  ganglion — on  age 


SEX 

AGE 

BODY 

BODY 

DIAMETERS 

RATIO  OF 
DIAMETER  OF 

WEIGHT 

LENGTH 

Cell 

Nucleus 

NUCLEUS  TO  CELL 

& 

89 

144 

176 

M  - 

21.90 

y 

12.90 

1 

1.69 

9 

89 

100 

156 

21.60 

13.00 

1 

1.66 

c? 

103 

232 

202 

24.60 

14.05 

1 

1.75 

9 

103 

203 

189 

24.20 

13.25 

1 

1.82 

c? 

123 

206 

193 

24.70 

13.12 

1 

1.88 

9 

123 

176 

187 

24.21 

13.14 

1 

1.84 

& 

116 

140 

177 

23.21 

12.60 

1 

1.84 

9 

116 

110 

172 

22.81 

12.50 

1 

1.82 

131 

310 

220 

28.80 

14.00 

1 

2.07 

9 

131 

205 

192 

26.00 

13.50 

1 

1.92 

c? 

136 

179 

188 

24.80 

12.79 

1 

1.94 

9 

136 

148 

182 

25.80 

13.79 

1 

1.87 

& 

154 

251 

212 

27.21 

15.21 

1 

1.79 

9 

154 

188 

189 

26.00 

13.45 

1 

1.93 

Diameters  of  Cells  and  Nuclei  in  micra 

* 

V 

v 

8- 

r - 

-* 

** 

* 

$ 

• 

A* — 

■*KtH 

XA 

rrr 

|*= 

r" 

r“~ 

— 

X 

Age  days 

80  90  100  110  120  130  140  150  160 


Chart  5  Based  on  table  10.  Showing  the  computed  diameters  of  the  cells 

and  their  nuclei,  according  to  sex,  on  age  in  days  (inbred  Albino).  Male - 

Female - 


304 


CHI  PING 


due  to  sex,  because  in  each  pair  the  male  has  a  greater  body 
weight  than  the  female. 

In  table  11  the  data  have  been  arranged  according  to  body 
weight.  Using  these,  chart  6  was  plotted.  In  only  one  instance 
is  the  value  for  the  female  below  that  for  the  male  in  the  case  of 
the  cells,  while  the  female  values  for  the  nuclei  are  always  above 
those  for  the  male. 

TABLE  11 


Giving  the  computed,  diameters  of  the  cells  and  their  nuclei  arranged  according  to 
body  weight.  The  same  data  as  in  table  10.  Inbred  albino  rats. 


SEX 

AGE 

BODY 

BODY 

DIAMETERS 

NUCLEUS  PLASMA 

WEIGHT 

LENGTH 

Cell 

Nucleus 

RATIOS 

9 

89 

100 

156 

21.60 

M 

13.00 

1:2.6 

9 

116 

110 

172 

22.81 

12.50 

1:5.1 

d1 

116 

140 

177 

23.21 

12.60 

1:5.2 

d1 

89 

144 

176 

21.90 

12.90 

1:3.9 

9 

136 

148 

182 

25.80 

13.79 

1:5.5 

9 

123 

176 

087 

24.21 

13.14 

1.5:2 

c? 

136 

179 

188 

24.80 

12.79 

1:6.3 

9 

154 

188 

189 

26.00 

13.45 

1:6.2 

9 

103 

203 

189 

24.20 

13.25 

1:5.1 

9 

131 

205 

192 

26.00 

13.50 

1:6.1 

d1 

123 

206 

193 

24.70 

13.12 

1:5.2 

c? 

103 

232 

202 

24.60 

14.05 

1:4.0 

d1 

154 

351 

212 

27.21 

15.21 

1:4.7 

d1 

131 

310 

220 

28.80 

14.00 

1:7.7 

30 


20 


10 


Diameters  of  Cells  and  Nuclei  in  micra- 


v 

/ 

•* 

** 

3 

X 

CL 

x- 

X 

• 

* 

3K 

— 

aody  weight- 

TTTT 

100 


200 


300 


Chart  6  Based  on  table  11  and  giving  the  computed  diameters  of  the  cells 
and  their  nuclei,  according  to  sex,  on  body  weight  (inbred  Albinos). 

Male - .  Female - . 


SYMPATHETIC  CELLS  I  ALBINO  RAT 


305 


As  shown  in  table  10,  the  female  is  smaller  in  size  than  the 
male  at  each  age,  the  female  at  equal  body  weight  must  therefore 
be  older,  consequently  the  cells  might  have  a  slightly  larger 
diameter  as  the  result  of  age,  but  the  difference  is  small.  It 
would  be  fair  to  say,  therefore,  that  the  cells,  as  well  as  the  nuclei, 
as  shown  in  chart  6,  do  indicate  a  sex  difference  although  it  is 
slight. 

This  result  supports  in  principle  the  earlier  findings  on  the 
standards  rats. 


TABLE  12 


To  illustrate  the  way  in  which  the  ‘ inbred ’  differ  from  the  ‘ standard ’  albino  rats  in 
respect  of  the  diameters  of  the  largest  cervical  sympathetic  cells 
and  their  nuclei.  Data  from  tables  1  and  11 


AGE 

BODY  WEIGHT 

DIAM] 

Cells 

ETERS 

Nucleus 

89 

122* 

21.75 

12.95 

124 

129 

28.80 

13.40 

/Absolute . 

-7.05 

-0.45 

HIGlGllCG  S  -|-V  . 

(Percentage . 

-32.0 

-4.0 

123 

191 

24.45 

13.13 

171 

161 

28.90 

13.00 

/Absolute . 

Difference 

(Percentage . 

-4.45 

-19.0 

+0.13 
+  1.0 

Inbred  albino  rat 
Stock  albino  rat 


Inbred  albino  rat 
Stock  albino  rat 


*The  values  given  are  the  average  for  the  male  and  female  in  each  instance. 


In  table  12  is  given  a  comparison  of  the  diameters  of  the  cells 
and  nuclei  of  the  inbred  Albino  with  those  of  the  stock  albino 
rat.  The  data  for  the  latter  have  been  selected  from  tables  2 
and  11.  The  sexes  are  combined. 

According  to  table  12,  the  inbred  has  its  largest  cells  in  the 
superior  cervical  sympathetic  ganglion  decidedly  smaller  than 
those  in  the  stock  albino  rat  of  approximately  the  same  body 
weight.  The  nucleus,  however,  shows  only  a  little  difference 
between  the  two  forms,  though  this  difference  is  in  the  same 
direction. 


306 


CHI  PING 


In  her  studies  on  inbreeding,  King  (T8)  states  that  the  closest 
form  of  inbreeding,  continued  for  many  generations,  has  not 
caused  a  diminution  in  the  average  body  weight  of  the  inbred 
rat  at  any  age,  and  that  through  the  selection  of  the  largest  and 
most  vigorous  animals  for  mating,  inbred  rats  are  superior  in 
body  size  to  the  stock  animals  reared  under  similar  environmental 
conditions.  Nevertheless,  our  data  as  they  stand  indicate  that 
in  the  inbred  rats  the  largest  cells  in  this  ganglion  are  clearly 
smaller  in  size  than  in  the  standard  strain.  It  seems  best  not  to 
comment  on  this  relation  until  studies  have  been  made  on  the 
wild  Norway,  and  these  I  hope  soon  to  undertake. 

SUMMARY 

A.  Based  on  the  data  for  the  1 standard ’  strain 

1.  Between  birth  and  maturity  the  largest  cells  in  the  superior 
cervical  sympathetic  ganglion  increase  about  55  per  cent  in 
diameter,  while  the  increase  in  the  nuclei  is  less  than  half  of  this 
amount. 

2.  The  growth  occurs  in  two  phases:  the  first  phase  of  rapid 
growth  ends  at  about  twenty-five  days  and  the  second  phase  of 
less  rapid  growth  continues  to  the  end  of  the  record.  The  present 
data  do  not  show  a  marked  alteration  in  rate  at  puberty. 

3.  The  size  of  these  cells  is  more  closely  related  to  the  body 
weight  than  to  the  age  of  the  rat,  but  there  is  a  marked  tendency 
after  puberty  for  the  females  to  have  slightly  larger  cells  than 
the  males  of  the  same  age. 

4.  The  nucleus-plasma  ratio  increases  from  1  to  4  at  birth  to 
about  1  to  12  at  maturity. 

5.  At  maturity  the  large  cells  may  be  classified  in  three  groups: 
1)  those  with  Nissl  bodies  accumulated  at  the  periphery  of. the 
cell;  2)  those  with  large  masses  of  Nissl  bodies  accumulated 
around  the  nucleus;  3)  those  with  larger  Nissl  bodies  mingled 
with  small  ones,  and  more  or  less  evenly  distributed  within  the 
cell.  Moreover,  a  few  binuclear  cells  are  found,  and  in  the  older 
rats  some  pigmented  cells  are  present. 


SYMPATHETIC  CELLS!  ALBINO  RAT 


307 


6.  Taking  the  ganglion  as  a  whole,  the  large  or  advanced  cells 
may  be  present,  though  in  very  small  numbers,  even  at  birth. 
This  number  is  slowly  increased  up  to  about  the  fifteenth  day, 
after  which  the  increase  is  more  rapid.  Correlated  with  this 
is  a  decrease  in  the  number  of  small  cells  which  are  transformed 
into  the  large  cells.  This  transformation  continues  during  the 
first  year  and  probably  throughout  life.  It  appears  to  occur 
slightly  earlier  in  the  female. 

B.  Based  on  the  data  for  the  ‘ inbred ’  strain 

7.  The  inbred  rats  ranged  from  89  to  154  days  in  age.  When 
the  values  for  the  diameters  of  the  cells  and  of  the  nuclei  were 
plotted  on  age,  these  values  were  greater  for  the  males.  The 
males  were  also .  consistently  greater  in  body  weight.  When 
the  values  were  plotted  on  body  weight,  the  values  for  the  females 
were  in  general  above  those  for  the  males.  In  this  case  the 
females  were  older  than  the  males  with  which  they  were  compared. 
It  seems  probable  that  at  like  ages  and  like  body  weights,  the 
females  would  show  slightly  higher  values,  but  this  may  be 
merely  an  expression  of  precocity  in  this  growth  change  in  the 
females. 

8.  When  these  cells  in  the  inbred  rats  are  compared  with  those 
in  the  standard  animals,  table  12,  it  is  seen  that  while  the  nuclei 
differ  but  little  in  diameter,  the  cells  in  the  standard  Albinos 
have  a  diameter  some  25  per  cent  greater  than  that  found  for  the 
inbred  cells.  It  is  to  be  noted  that  this  difference  in  diameter 
would  make  the  volume  of  these  cells  in  the  standard  Albino 
about  twice  that  in  the  inbred,  while  the  nuclei  differ  but  slightly. 
This  difference  in  the  cells  is  definite,  but  the  significance  of  it  is 
not  discussed  here. 

9.  The  ratios  of  the  diameter  of  the  nucleus  to  that  of  the 
cell  are  in  the  inbred  distinctly  less  than  in  the  standard  Albino, 
within  the  same  age  limits.  Compare  data  in  table  1  with  those 
in  table  10. 

10.  The  nucleus  plasma  ratios  in  the  inbred  are  only  about 
half  as  great  as  in  the  corresponding  cells  of  the  standard  Albino. 
Compare  data  in  table  2  with  those  in  table  11. 


308 


CHI  PING 


LITERATURE  CITED 

Apolant,  H.  1896  Ueber  die  sympathischen  Ganglienzellen  der  Nager.  Arch, 
f.  mikr.  Anat.,  Bd.  47,  S.  461-471. 

Carpenter,  F.  W.,  and  Conel,  J.  L.  1914  A  study  of  ganglion  cells  in  the 
sympathetic  nervous  system,  with  special  reference  to  intrinsic  sensory 
neurones.  Jour.  Comp.  Neur.,  vol.  24,  pp.  269-279. 

Donaldson,  H.  H.  1915  The  rat.  Reference  tables  and  data  for  the  albino 
rat  (Mus  norvegicus  albinus)  and  the  Norway  rat  (Mus  norvegicus). 
Memoirs  of  The  Wistar  Institute  of  Anatomy  and  Biology,  no.  6. 

1917  Growth  changes  in  the  mammalian  nervous  system.  The 
Harvey  lectures,  series  12,  pp.  133-150. 

Donaldson,  H.  H.  and  Nagasaka,  G.  1918  On  the  increase  in  the  diameters  of 
nerve-cell  bodies  and  of  the  fibers  arising  from  them — during  the  later 
phases  of  growth  (albino  rat).  Jour.  Comp.  Neur.,  vol.  29,  pp.  529-552. 

Dunn,  Elizabeth  H.  1912  The  influence  of  age,  sex,  weight  and  relationship 
upon  the  number  of  medullated  nerve  fibers  and  on  the  size  of  the 
largest  fibers  in  the  ventral  root  of  the  second  cervical  nerve  of  the 
albino  rat.  Jour.  Comp.  Neur., -vol.  22,  pp.  131-157. 

Gaskell,  Walter  H.  1920  The  involuntary  nervous  system.  Longmans, 
Green  &  Co.  New  York 

King,  Helen  D.  1910  The  effects  of  various  fixatives  on  the  brain  of  the 
albino  rat,  with  an  account  of  a  method  of  preparing  this  material 
for  a  study  of  the  cells  in  the  cortex.  Anat.  Rec.,  vol.  4,  pp.  214-244. 

1918  Studies  on  inbreeding.  I.  The  effect  of  inbreeding  on  the  growth 
and  variability  in  the  body  weight  of  the  albino  rat.  Jour.  Exp.  Zook, 
vol.  26,  pp.  1-54. 

Kuntz,  A.  1910  The  development  of  the  sympathetic  nervous  system  in  mam¬ 
mals.  Jour.  Comp.  Neur.,  vol.  20,  pp.  212-259. 


PLATE 


309 


t 


4 


PLATE  1 


EXPLANATION  OF  FIGURES 

Cells  from  the  superior  cervical  sympathetic  ganglion  of  the  albino  rat.  Fig¬ 
ures  1  to  7  magnified  in  plate  by  2000. 

1  An  advanced  cell  and  several  young  cells;  male,  one  day  old. 

2  An  advanced  cell  with  Nissl  bodies  evenly  distributed;  male,  five  days  old. 

3  A  cell  with  Nissl  bodies  accumulated  at  the  periphery,  common  between 
twenty  days  and  sixty  days;  female,  twenty  days. 

4  A  cell  with  Nissl  bodies  accumulated  around  the  nucleus,  common  between 
twenty  days  and  sixty  days  and  also  found  at  later  ages;  male,  sixty  days  old. 

5  A  cell  with  larger  Nissl  bodies  more  or  less  evenly  distributed  common 
after  one  hundred  days;  female,  124  days  old. 

6  A  binuclear  cell;  female,  one  day  old. 

7  A  binuclear  cell;  male,  one  year  old. 


310 


63  en 


THt  LIBRARY 
OF  THE 

<J«?  '  '  ■  M  , 


author’s  abstract  of  this  paper  issued  Reprinted  from  The  Journal  of  Comparative 
by  THE  bibliographic  service,  September  26  Neurology,  Vol.  33,  No.  4,  October,  1921 


ON  THE  GROWTH  OF  THE  LARGEST  NERVE  /CELLS 
IN  THE  SUPERIOR  CERVICAL  SYMPATHETIC 
GANGLION  OF  THE  NORWAY  RAT 

chi  ping 

The  Wistar  Institute  of  Anatomy  and  Biology 

FIVE  CHARTS 

INTRODUCTION 

This  study  is  a  continuation  of  my  first  work  “On  the  growth 
of  the  largest  nerve  cells  in  the  superior  cervical  sympathetic 
ganglion  of  the  albino  rat  from  birth  to  maturity”  (Ping,  ’21). 

In  that  paper  the  significance  of  the  age,  the  size  of  the  animal, 
and  of  sex  on  the  growth  of  the  cells  was  examined,  and  an  un¬ 
expected  difference  in  the  size  of  these  cells  was  found  in  the 
‘inbred’  as  contrasted  with  ‘standard’  strain  of  Albinos.  It 
was  deemed  important,  therefore,  to  examine  the  Norway  rat 
in  the  same  way  in  order  to  determine  how  the  size  and  the 
growth  changes  in  these  cells  were  related  in  the  wild  Norway 
to  those  found  in  the  two  domesticated  albino  strains. 

MATERIAL  AND  TECHNIQUE 

The  eighty-five  specimens  of  the  wild  Norway  used  in  this 
study  belong  to  two  groups  from  different  sources.  One  group, 
comprising  twenty-two  individuals,  was  reared  at  The  Wistar 
Institute,  and  the  ages  of  these  animals  range  from  one  day  to 
134  days. 

The  other  group  of  sixty-three  animals  was  collected  from 
different  localities  in  Philadelphia  and  its  vicinity,  and  the  ages 
of  these  are  unknown.  Their  body  weights  range  from  37  to 
402  grams,  corresponding  to  ages  from  twenty  days  to  three 
years,  as  generally  estimated. 

313 


i 


314 


CHI  PING 


/ 


The  technique  employed  in  preparing  the  specimens  is  the 
same  as  that  given  in  my  former  paper.  The  trapped  rats  were 
carefully  examined  when  dissected,  and  all  the  specimens  used 
were  considered  normal.  As  the  ages  of  the  trapped  rats  were 
unknown,  the  determination  of  the  percentage  of  water  in  the 
brain  was  made  in  each  case,  since  by  this  means  the  approximate 
age  of  the  animal  may  be  estimated,  as  pointed  out  by  Donald¬ 
son  (TO),  Donaldson  and  Hatai  (Tl,  and  T6). 

TABLE  1 


Giving  according  to  body  weight  the  computed  diameters  of  the  largest  cells  and 
nuclei  in  the  superior  cervical  ganglion  of  the  Norway  rat.  Sexes  separated. 
Data  condensed.  Thirteen  groups 


FORTY-THREE  MALES 

FORTY-TWO  FEMALES 

Number 
of  cases 

Body- 

weight 

average 

Computed  diameter 

Computed  diameter 

Body 

weight 

average 

Number 
of  cases 

Nucleus 

Cell 

Cell 

Nucleus 

grams 

U 

U 

M 

M 

grams 

1 

6 

9.9 

17.2 

16.5 

9.6 

6 

1 

3 

15 

12.9 

22.8 

22.5 

12.5 

14 

3 

5 

35 

12.4 

23.4 

23.2 

11.7 

28 

2 

3 

76 

13.0 

25.5 

25.2 

13.0 

31 

1 

3 

104 

13.1 

26.5 

24.3 

12.7 

51 

8 

2 

117 

13.2 

27.1 

26.0 

13.0 

73 

2 

3 

157 

13.3 

26.1 

24.9 

13.0 

103 

4 

3 

186 

13.4 

27.9 

28.3 

13.3 

157 

4 

5 

220 

13.6 

29.7  , 

27.7 

13.0 

179 

6 

4 

244 

14.0 

31.3 

26.6 

12.8 

192 

3 

3 

276 

13.5 

33.3 

27.8 

12.7 

214 

3 

5 

323 

14.0 

33.0  * 

31.6 

13.7 

227 

2 

3 

385 

13.7 

31.0 

32.1 

13.9 

258 

3 

In  measuring  the  cells  and  the  nuclei  of  the  superior  cervical 
ganglion  I  followed  the  same  procedure  as  in  my  former  study 
of  the  Albino.  The  data  represented  by  the  computed  diameters 
of  the  cells  and  nuclei,  and  their  ratios,  together  with  the  sex, 
age,  body  length,  and  body  weight,  as  well  as  the  percentage 
of  water  in  the  brain,  were  tabulated  in  the  first  instance  for 
each  individual  according  to  increasing  body  weight,  but  these 
data  have  been  condensed  for  the  purpose  of  this  paper — and 
only  the  condensed  tables  will  be  used  for  discussion.  The 


SYMPATHETIC  CELLS:  NORWAY  RAT 


315 


individual  data  are  on  file  in  the  archives  of  The  Wistar  Institute 
and  available  there  for  reference. 

The  values  for  the  diameters  of  the  cells  and  their  nuclei  are 
the  averages  of  measurements  on  the  twenty  largest  cells  in  each 
ganglion. 

GROWTH  OF  THE  CELLS 

A.  In  relation  to  body  weight 

The  computed  diameters  of  the  cells  and  the  nuclei  of  the 
eighty-five  cases  have  been  condensed  to  thirteen  groups  for 


30 


20 


10 


0  50  100  150  200  250  300  350  400 

Chart  1  Based  on  table  1  and  giving  the  computed  diameters  of  the  cells 
and  their  nuclei  according  to  sex — on  body  weight  in  grams.  Wild  Norway  rat. 
Males - Females - 

each  sex  and  arranged  according  to  body  weight  as  shown  in 
table  1.  From  these  data  chart  1  was  plotted. 

The  graphs  in  chart  1  show  both  the  cell  bodies  and  the  nuclei 
as  growing  rapidly  up  to  a  body  weight  of  15  grams,  but  after 
that  period  they  grow  more  gradually.  The  graphs  for  the 
males  and  females  run  close  together  at  all  body  weights,  and 
there  is  no  indication  of  the  difference  according  to  sex  shown  in 
chart  2  for  the  Albino  (Ping,  ?21). 


Diameters  of  Cells  and  Nuclei  in  micra 

/ 

-• 

/ 

*- 

— 

* 

f- 

— 

£ 

wz 

"  - 

A- 

t 

/ 

• 

f 

fH 

*•- 

*•- 

- 

.  - 

*- 

-V5 

... 

-* 

/ 

'■i 

4 

B 

ody  weight— gms. 

50159 


316 


CHI  PING 


B.  In  relation  to  body  length 

Following  the  procedure  just  used,  the  condensed  data  have 
been  arranged  to  show  the  relations  of  the  cell  diameters  accord¬ 
ing  to  increasing  body  length,  and  are  given  in  table  2.  There 
are  thirteen  groups  for  the  males  and  eleven  for  the  females. 
The  corresponding  graphs  are  plotted  in  chart  2.  According 

TABLE  2 


Giving  according  to  body  length  the  computed  diameters  of  the  largest  cells  and  nuclei 
in  the  superior  cervical  ganglion  of  the  Norway  rat.  Sexes  separated.  Data 
condensed 


MALE 

FEMALE 

Number 

Body 

length 

Computed  diameter 

Computed  diameter 

Body 

length 

Number 

of  cases 

average 

Nucleus 

Cell 

Cell 

Nucleus 

average 

of  cases. 

mm. 

U 

M 

U 

mm. 

1 

53 

9.9 

17.2 

16.5 

9.6 

50 

1 

2 

71 

12.5 

21.9 

22.5 

12.5 

71 

3 

1 

84 

13.8 

24.4 

23.9 

12.1 

103 

3 

2 

104 

12.6 

23.6 

23.4 

12.8 

114 

1 

3 

112 

12.3 

23.3 

24.6 

12.8 

123 

5 

3 

144 

12.9 

25.5 

24.7 

12.7 

130 

3 

5 

167 

13.1 

26.8 

25.7 

12.9 

146 

3 

5 

189 

13.3 

26.4 

27.3 

13.2 

184 

12 

6 

209 

13.5 

29.8 

28.3 

12.8 

202 

6 

3 

214 

14.8 

32.6 

28.9 

13.5 

213 

2 

5 

225 

13.5 

32.6 

31.5 

13.7 

222 

3 

4 

233 

13.8 

32.4 

3 

251 

13.7 

31.1 

to  the  graph's,  there  seem  to  be  two  periods  in  which  the  diameter 
of  the  cell  is  showing  a  rapid  growth;  one  period  at  a  body  length 
of  about  80  mm.  and  the  other  at  a  body  length  of  about  200  mm. 
Without  entering  into  the  details,  it  will  be  sufficient  to  point 
out  that  both  periods  are  those  in  which  the  body  weight  is 
increasing  rapidly  in  relation  to  the  body  length,  and  it  is  prob¬ 
ably  the  influence  of  the  body  weight  which  appears  in  the 
graphs.  At  the  same  time  there  is  no  sex  difference  to  be  seen 
in  the  diameters  of  either  the  cells  or  their  -nuclei. 


SYMPATHETIC  CELLS:  NORWAY  RAT 


317 


C.  In  relation  to  observed  age 

The  rats  with  known  ages  form  a  separate  series  for  the  pres¬ 
ent  discussion.  The  computed  diameters  of  the  cells  and  the 
nuclei  are  given  in  table  3  according  to  age.  Examination  of 
the  table  reveals  that  the  cells  and  nuclei  grow  comparatively 
fast  during  the  first  twenty-five  days  of  life.  In  order  to  show 
the  contrast  between  the  early  growth  and  that  which  follows, 
data  selected  from  table  3  have  been  arranged  in  table  4. 


'  Chart  2  Based  on  table  2  and  giving  the  computed  diameters  of  the  cells 
and  their  nuclei  according  to  sex — on  body  length  in  millimeters.  Wild  Norway 
rat.  Males  ■ — - Females - 

Table  4  shows  that  at  the  end  of  twenty-five  days  the  cells 
and  the  nuclei  have  increased  in  diameter  1.31  and  1.14  times, 
respectively,  for  the  male,  and  1.43  and  1.25  times  for  the  female; 
while  the  increase  from  25  days  to  134  days — a  period  which 
is  more  than  five  times  as  long — is  1.19  for  the  cells  and  1.21 
for  the  nuclei  of  the  male  and  1.04  for  the  cells  and  1.06  for  the 
nuclei  of  the  female. 

The  graphs  in  chart  3  illustrate  the  fact  that  during  the  first 
twenty-five  days  there  occurs  a  sudden  and  rather  irregular 
increase,  which  is  followed  by  a  slow  advance.  No  clear  indi¬ 
cation  of  a  difference  according  to  sex  is  to  be  seen. 


318 


CHI  PING 


TABLE  3 

Giving  according  to  age  the  computed  diameters  of  the  cells  and  nuclei  in  the  superior 
cervical  ganglion  of  the  Norway  rat.  Sexes  separated.  From  detailed  record 


SEX 

AGE 

• 

COMPUTED  DIAMETERS 

RATIOS  OF  DIAMETER 
NUCLEUS  TO 

Cell 

Nucleus 

DIAMETER  OF  CELL 

d1 

days 

1 

M 

17.19 

M 

9.85 

1  : 1.74 

9 

1 

16.51 

9.60 

1  :  1.72 

d1 

5 

22.20 

12.41 

1  :  1.79 

9 

5 

22.40 

12.30 

1  :  1.82 

d1 

10 

21.66 

12.50 

1  :  1.74 

9 

10 

22.21 

12.60 

1  :  1.75 

d1 

15 

24.40 

13.82 

1  :  1.76 

9 

15 

22.82 

12.60 

1  :  1.81 

d1 

19 

26.00 

13.86 

1  :  1.88 

9 

19 

25.21 

13.00 

1  : 1.94 

9 

• 

25 

22.61 

11.25 

1  :  2.01 

9 

25 

23.80 

12.06 

1  :  1.86 

d 

28 

26.00 

13.40 

1  :  1.94 

d1 

31 

21.21 

11.25 

1  : 1.89 

d1 

31 

21.02 

10.55 

1  :  1.99 

9 

60 

27.22 

14.20 

1  : 1.93 

d1 

65 

25.00 

13.04 

1  :  1.92 

9 

65 

26.24 

13.49 

1  :  1.95 

d* 

80 

23.25 

13.40 

1  : 1.73 

9 

80 

23.41 

12.80 

1  : 1.82 

d1 

134 

27.00 

13.70 

1  : 1.97 

9 

134 

24.70 

12.85 

1  :  1.84 

SYMPATHETIC  CELLS  I  NORWAY  RAT 


319 


TABLE  4 

Increase  in  diameters  of  cells  and  nuclei  at  three  different  ages 


DIAMETERS 

SEX 

AGE 

Cell 

Nucleus 

days 

cf 

1 

17.19 

9.85 

$ 

1 

16.61 

9.60 

cf 

25 

• 

22.61 

11.25 

$ 

25 

23.80 

12.06 

c? 

134 

27.00 

13.70 

$ 

134 

24.70 

12.85 

Ratios  between  1  day  and  25  days 

fd1 

1  : 1.31 

1  :  1.43 

1  : 1.14 

1  :  1.25 

Ratios  between  25  and  134  days  . . 

. i 

rc? 

1? 

1  :  1.19 

1  :  1.04 

1  :  1.21 

1  :  1.06 

Diameters  of  Cells  and 

Nucle 

in 

micra 

r 

^  " 

* 

* 

ft 

•.  A 

s ' 

_ 

-- 

* 

t1 

f 

V 

* 

* 

V 

V' 

• 

a 

• 

r* 

t 

HL * 

a* 

c 

i. 

Anp- 

-Have 

_ i 

30 


20 


10 


0  20  50 


100 


200  200  300  400 


Chart  3  Based  on  table  3  and  giving  the  computed  diameters  of  the  cells  and 
their  nuclei  according  to  sex — on  age  in  days.  Wild  Norway  rat.  The  values 
for  one  female  at  450  days  are  given  in  the  chart.  This  case  is  not  entered  in 
table  3.  At  200  days,  as  indicated  by  a  break  in  the  graph,  the  time  unit  is 
changed — one  division  being  made  equal  to  twenty-five  days  instead  of  ten  days  as 
heretofore.  Males -  Females  - - 


320 


CHI  PING 


To  return  to  table  3,  the  ratios  between  the  cell  and  nucleus 
tend  to  increase  up  to  the  age  of  twenty-five  days;  from  that 
time  on  the  ratio  in  every  case  is  almost  1:1.9.  It  should  be 
noticed,  moreover,  that  there  is  during  this  later  period  no  in¬ 
crease  in  the  ratios  as  the  animal  increases  in  age  or  in  size. 
This  fact  will  be  discussed  later  on. 


TABLE  5 

Giving  according  to  percentage  of  water  in  the  brain  the  computed  diameters  of  the 
cells  and  nuclei  in  the  superior  cervical  ganglion  of  the  Norway  rat.  Sexes  sep¬ 
arated.  Data  condensed 


MALE 

Mean 

body 

weights 

Number 

of 

Percentage 
of  water 
in  brain, 

Computed 

diameter 

eases 

average 

Nucleus 

Cell 

100 

1 

80.4 

M 

13.4 

n 

26.0 

54 

2 

79.5 

12.3 

24.2  ; 

153 

5 

78.7 

13.3 

28.4 

172 

5 

78.3 

13.3 

28.2 

258 

7 

78.1 

14.1 

32.4 

194 

2 

77.7 

13.0 

28.9 

253 

3 

n  .4 

14.1 

31.4 

331 

7 

76.8 

13.5 

30.8 

FEMALE 


Computed 

diameter 

Percent¬ 
age  of 
water  in 

Number 

of 

Mean 

body 

weights 

Cell 

Nucleus 

orain, 

average 

cases 

M 

25.5 

M 

12.7 

80.4 

2 

68 

23.7 

12.6 

79.6 

5 

46 

26.6 

13.0 

78.7 

4 

129 

27.2 

13.1 

78.5 

5 

164 

29.5 

13.5 

78.2 

5 

203 

30.2 

13.5 

77.8 

2 

205 

26.6 

12.5 

77.4 

2 

175 

28.2 

12.8 

77.0 

5 

203 

D.  In  relation  to  the  percentage  of  water  in  the  brain  as  an 

indication  of  age 

Accepting  the  conclusion  (Donaldson,  TO)  that  the  percentage 
of  water  in  the  central  nervous  system  is  more  closely  correlated 
with  age  than  with  body  weight  and  brain  weight,  it  was  thought 
worth  while  to  study  the  growth  of  these  cells  in  relation  to  the 
percentage  of  water  in  the  brain,  in  order  to  supplement  what 
has  been  presented  in  the  preceding  paragraph,  based  on  ani¬ 
mals  of  known  ages. 

Table  5  is,  therefore,  to  a  certain  extent,  a  continuation  of 
table  3.  For  each  sex  there  are  eight  entries  based  on  the  con¬ 
densed  data,  those  cases  with  known  ages  being  excluded.  The 
corresponding  graphs  appear  in  chart  4.  According  to  Don- 


SYMPATHETIC  CELLS  I  NORWAY  RAT 


321 


aldson  (’ll)  the  percentage  of  water  in  the  central  nervous  system 
of  the  Albino  and  Norway  rat  at  like  ages  is  nearly  the  same, 
so  the  ages  of  the  Norway  rats  whose  percentages  of  water  are 
known  may  be  obtained  from  table  74  of  ‘The  Rat’  (Donaldson, 
T5)  and  the  growth  of  the  cells  as  shown  in  chart  4  can  be  trans¬ 
lated  into  age.  Using  this  procedure,  the  curves  in  chart  4 
represent  the  gradual  growth  from  twenty-five  days  of  age 
to  maturity. 


uicimeiens  oi  ^eus  ana  iNucie 

in 

micra 

1 

* 

A 

/ 

Jir 

%r 

•  ^ 

-  „ 

-  " 

7?. 

-54 

A 

3*— 

““ 

**~1 

r*- 

-- 

— V 

Porrentanp  watpr 

30 


20 


10 


81  80  79  78  77  76 


Chart  4  Based  on  table  5  and  giving  the  computed  diameters  of  the  cells 
and  their  nuclei  according  to  sex — on  percentage  of  water  in  the  brain.  Wild 
Norway  rat.  Males -  Females  - 


The  examination  of  table  5  enables  us  to  see  that  in  general 
the  female  has  a  slightly  higher  percentage  of  water  in  the  brain 
than  the  male,  due  probably  to  the  smaller  absolute  size  of  the 
brain  (Donaldson,  ’16),  but  the  cells  of  the  male  exceed  in  diam¬ 
eter  those  of  the  female  in  seven  out  of  eight  cases. 


MORPHOLOGY  OF  THE  LARGE  CELLS 

The  general  morphological  changes  in  the  large  cells  from 
birth  to  maturity  are  similar  to  those  in  the  cells  of  the  Albino. 
The  large  cells  of  the  first  few  days  are  much  alike  in  the  two 
forms.  The  distribution  of  Nissl  granules  and  the  tendency  to 
accumulate  at  different  regions  in  the  cell  in  the  later  ages  are 
also  alike  in  the  two  forms.  There  is,  however,  some  difference 


322 


CHI  PING 


between  the  Albino  and  the  Norway  rat  in  regard  to  the  degree 
of  aggregation  of  the  Nissl  bodies  in  the  cells.  Thus,  in  the 
cells  of  the  Norway,  these  are  not  so  densely  crowded  either  at 
the  periphery  or  around  the  nucleus  as  in  the  cells  of  the  Albino. 

Furthermore,  the  space  left  at  one  region  through  the  crowd¬ 
ing  of  Nissl  bodies  toward  another  is  not  so  clear.  There  is 
therefore  always  found  a  gradual  thinning  out  of  the  granules 
toward  the  periphery  or  the  nucleus  whenever  the  accumulation 
of  them  takes  place  in  a  reverse  direction. 

When  the  Norway  rat  reaches  twenty  days  of  age,  we  find 
in  the  cells  of  the  superior  cervical  ganglion  a  tendency  for  the 
Nissl  bodies  to  aggregate  at  the  periphery,  though  the  region 
around  the  nucleus  is  by  no  means  devoid  of  thepi.  Likewise, 
when  the  Norway  rat  is  about  sixty  or  more  days  old,  the  Nissl 
bodies  tend  to  accumulate  around  the  nucleus,  while  the  periph¬ 
ery  still  has  some  of  them  thinly  scattered.  Unless  carefully 
examined,  therefore,  the  distribution  of  the  Nissl  bodies  in  the 
cells  at  twenty  to  sixty  days  and  in  those  sixty  days  and  later 
would  appear  the  same,  i.e.,  as  if  they  were  evenly  distributed. 

Like  the  Albino,  the  distribution  of  the  granules  in  the  cells 
of  the  older  Norways  is  fairly  even.  On  the  whole,  then,  there 
is  no  marked  distinction  between  the  two  forms,  so  far  as  the 
general  morphology  of  these  cells  is  concerned. 

According'to  Gaskell  (’18),  both  the  motor  and  the  inhibitory 
cells  are  found  in  the  sympathetic  ganglion,  and  Cajal  (’ll), 
using  the  Golgi  method,  shows  in  the  superior  cervical  ganglion 
of  a  mouse  several  days  old  cells  which  appear  to  represent  three 
different  types  (fig.  550,  B,  C,  and  D).  That  the  four  types 
of  cells  (Ping,  ’21)  found  in  the  superior  cervical  ganglion  of 
both  the  Albino  and  Norway  rat  are  correlated  with  the  several 
functions  of  the  ganglion  is  by  no  means  determined,  but,  gen¬ 
erally  speaking,  we  should  expect  that  the  morphological  dis¬ 
tinctions  would  have  a  functional  significance. 


SYMPATHETIC  CELLS:  NORWAY  RAT 


323 


Binuclear  cells 

The  number  of  the  binuclear  cells  in  one  ganglion  in  each 
case  is  recorded  in  table  6.  Generally  speaking,  we  may  say 
that  this  type  of  cell  is  found  through  the  whole  span  of  life. 

TABLE  6 

Norway  rat:  Data  for  eighty  individuals  arranged  in  eighteen  groups  according 
to  the  decreasing  value  of  the  percentage  of  water  in  the  brain.  This  is  indicative 
of  increasing  age.  Under  the  ‘ number  of  cells’  the  number  of  any  class  of  cells  in 
one  ganglion  of  each  individual  in  which  such  cells  occur  is  given.  Thus  in  the 
first  group  one  individuals  showed  three  binuclear  cells,  but  no  pigmented  or  vacuo¬ 
lated  cells  were  found.  In  the  fifteenth  group  binuclear  cells  were  found  in  four 
out  of  the  five  individuals,  pigmented  cells  in  four,  and  vacuolated  cells  in  one 


NUMBER  OF 
CASES 

AVERAGE 
PERCENT¬ 
AGE  OF 
WATER  IN 

THE 

BRAIN 

AVERAGE 

BODY 

WEIGHT 

NUMBER  OF  CELLS  IN  INDIVIDUAL  CASES — ZEROS  OMITTED 

M. 

F. 

Total 

Binuclear 

Pigmented 

Vacuo¬ 

lated 

grams 

1 

2 

3 

88.33 

11 

3 

— 

— 

2 

1 

3 

87.98 

11 

1 

— 

— 

2 

1 

3 

84.42 

21 

3,  3 

.  — 

— 

— 

3 

3 

81.45 

29 

1,  1 

— 

— 

2 

2 

4 

80.30 

67 

1 

— 

— 

1 

3 

4 

79.83 

40 

1,  1,  1 

— 

— 

3 

1 

4 

79.43 

46 

1,  1,  1 

— 

— 

3 

2 

5 

78.87 

119 

1,  5,  8,  3 

— 

— 

2 

3 

5 

78.69 

120 

1,  5,  3,  3,  1 

O 

— 

1 

4 

5 

78.47 

183 

5,  9,  2,  4 

1 

— 

3 

2 

5 

78.41 

123 

3,  1 

— 

— 

4 

1 

5 

78.29 

201 

2,  2,  4,  14 

2,  13 

— 

2 

3 

5 

78.14 

220 

5,  2,  10,  1 

1,3 

3 

3 

2 

5 

78.01 

236 

7,3 

1,3,  1 

3 

4 

1 

5 

77.60 

240 

2,  2,  10,  3 

9,  3,  15,  4 

1 

1 

4 

5 

77.25 

189 

5,  2,  4,  2 

85,  3,  2,  6 

— 

2 

3 

5 

77.00 

279 

2,  1,  1,  2,  2 

1,  2,5 

— 

5 

1 

6 

76.66 

307 

9,  3,  3,  4 

2,  5,  1,  37,  15,  1 

1 

There  are,  however,  exceptions,  since,  as  the  table  shows,  this 
type  of  cell  is  present  in  all  the  individuals  composing  a  group 
in  two  instances  only. 

As  can  be  seen,  binuclear  cells  appear  usually  in  very  small 
number  and  frequentty  only  one  is  found  in  the  entire  ganglion^ 


324 


CHI 


PING 


and  the  maximum  number  of  these  cells  is  never  above  ten. 
There  seems  to  be  a  tendency  for  the  binuclear  cells  to  increase 
in  number  during  the  middle  age  of  the  animal.  The  diameters 
of  some  of  these  cells  and  those  of  their  two  nuclei,  as  well  as  the 
nucleus-plasma  ratios  derived  from  these  diameters,  are  recorded 
in  table  7. 

According  to  table  7,  the  nucleus-plasma  relation  is  1:4.6 
in  a  very  young  rat  and  1:4.1  in  an  old  rat,  as  indicated  by  the 
body  weight,  and  throughout  the  series  the  values  are  fairly 
constant,  though  with  a  slight  tendency  to  diminish.  This 
agrees  with  what  has  been  found  in  the  Albino  and  shows  that 

TABLE  7 


Diameters  of  some  of  the  binuclear  cells  and  of  the  two  nuclei  in  each  of  them.  Data 
arranged  according  to  body  weight.  The  nucleus-plasma  ratios  are  shown  in  the 
last  column.  Norway  rat 


BODY  WEIGHT 

Cell 

DIAMETER  OF 

Two  nuclei 

RATIO  OF  VOLUME  OF 

CYTOPLASM  TO  VOLUME  OF 
TWO  NUCLEI 

grams 

U 

y 

13.6 

25.0 

11.6  +  10.7 

1  :  4.6 

33.0 

29.9 

13.4  +  13.4 

1  :  4.6 

115.0 

26.3 

13.4+  8.9 

1  :  4.8 

169.2 

28.1 

13.4  +  12.9 

1  : 3.9 

243.2 

27.7 

12.0  +  13.4 

1  : 4.1 

230.2 

28.1 

13.4  +  13.4 

1  : 3.6 

in  the  binuclear  cells  there  is  an  increase  in  the  nuclear  mass 
which  is  not  accompanied  by  the  same  enlargement  of  the  cyto¬ 
plasm,  as  is  found  in  mononuclear  cells.  In  their  nucleus-plasma 
relation,  therefore,  these  binuclear  cells  are  like  very  young  cells, 
and  in  the  older  animals  at  least  they  certainly  do  not  represent 
two  normal  mononuclear  cells  pressed  together. 

Pigmented  cells 

It  is  somewhat  surprising  to  find  that  the  pigmented  cells 
in  the  superior  cervical  ganglion  of  the-  Norway  are  not  very 
numerous,  as  table  6  shows.  In  no  case  were  they  found  in  all 
of  the  individuals  of  a  group.  They  do  not  appear  in  the  young 


SYMPATHETIC  CELLS:  NORWAY  RAT 


325 


animal,  the  first  being  found  in  my  series  at  a  body  weight  of 
120  grams.  In  this  case  the  percentage  of  water  in  the  brain 
was  78.69,  which  corresponds  to  the  age  of  eighty-eight  days — 
this  happens  to  be  exactly  the  age  at  which  they  first  appeared 
in  the  Albino.  The  number  of  the  pigmented  cells  tends  to 
increase  as  the  animal  grows  older.  There  are  two  cases  among 
the  older  rats  which  show  large  numbers  of  pigmented  cells, 
but  most  ganglia  have  only  a ‘few,  even  at  the  later  ages.  There 
is  less  increase  in  the  number  of  these  cells  in  the  Norway,  as 
contrasted  with  the  Albino,  than  we  should  have  expected.  The 
pigment  granules  are  black  or  greenish  black  in  color.  It  was 
a  matter  of  some  surprise  to  find  that  in  the  gray  pigmented 
rat  the  cells  contained  hardly  more  pigment  than  appeared  in 
the  Albino. 

Vacuolization  of  the  cells 

Incidentally  vacuoles  have  been  noted  in  a  very  few  of  the 
cells  in  the  superior  cervical  ganglion  of  the  Norway,  although 
none  were  observed  in  the  Albino.  Out  of  eighty  cases  only 
eight  showed  vacuoles  in  the  cells  and  in  an  entire  ganglion 
only  one  to  three  vacuolated  cells  have  been  found  (table  6). 
Most  of  these  cells  have  but  one  vacuole,  which  is  oval  in  shape, 
and  which  may  lie  close  either  to  the  nucleus  or  to  the  periph¬ 
ery,  but  in  one  cell  two  vacuoles  were  found.  The  size  of  the 
vacuole  varies;  generally  it  is  smaller  than  the  nucleus,  rarely 
larger.  It  resembles  the  nucleus  in  outline,  but,  owing  to  the 
absence  of  any  internal  structure,  can  be  recognized  without 
difficulty.  All  the  vacuolated  cells  were  found  in  older  rats. 

Increase  in  the  number  of  the  large  cells 

In  counting  the  large  cells  found  during  the  first  twenty-five 
days,  I  followed  the  procedure  previously  used  for  the  Albino. 
The  cells  of  the  Norway  are  small  as  compared  with  those  of 
the  Albino,  especially  at  birth,  so  I  have  extended  the  limiting 
values,  19  to  25  /x,  which  were  used  for  the  diameters  in  counting 
the  large  cells  of  the  Albino,  to  16  to  25  p  for  the  Norway. 


326 


CHI  PING 


Table  8  gives  the  number  of  these  large  cells  recorded  in  the 
ganglion  for  each  sex  during  the  first  twenty-five  days. 

There  are  a  few  advanced  cells  and  a  few  comparatively  large 
cells  at  birth,  or  just  after,  but  the  number  is  strikingly  small. 
By  the  end  of  the  fifth  day  there  is  a  great  increase  in  number — 
about  twenty  times  that  of  the  preceding  stage.  Then  the 

TABLE  8* 

Increase  in  number  of  large  and  advanced  cells ,  16  to  25  \x  in  diameter,  during  the 
first  twenty-five  days  of  age.  The  ratios  for  the  increase  in  the  total  number  for 
both  sexes  between  one  day  and  nineteen  days  stand  at  the  foot  of  the  last  column. 
Superior  cervical  sympathetic  ganglion.  Norway  rat 


SEX 

AGE 

BODY  WEIGHT 

NUMBER  OF  LARGE  CELLS 

days 

grams 

<F 

1 

5.9 

22 

9 

1 

5.6 

24 

c? 

5 

12.7 

416 

9 

5 

13.4 

515 

d71 

10 

13.6 

417 

9 

10 

13.5 

530 

d” 

15 

17.6 

833 

9 

15 

13.6 

827 

cF 

19 

31.1 

3, 066 

9 

19 

31.1 

3, 084 

9 

25 

28.5 

3, 074 

Ratios  between  1  and  19  days . 

. {t 

1  :  139.3 

1  :  129.0 

increase  is  slow  and  slight  until  the  age  of  fifteen  days.  At  this 
time  the  cells  again  show  a  considerable  increase  in  their  number, 
and  this  is  still  more  marked  at  nineteen  and  twenty-five  days. 
Thus  the  greatest  increase  in  number  of  the  large  cells  is  between 
one  and  five  days,  and  again  between  fifteen  and  nineteen  as 
in  the  case  of  the  Albino  (Ping,  ’21,  table  6). 


SYMPATHETIC  CELLS:  NORWAY  RAT 


•327 


The  ratio  of  increase  is  a  trifle  higher  for  the  male  Norway, 
as  was  found  for  the  male  Albino;  indeed,  the  relations  of  the 
ratios  according  to  sex  are  strikingly  similar  in  the  two  strains. 

As  will  be  seen  by  comparing  the  ratios  (1  to  19  days)  for  the 
Norway  with  those  (1  to  20  days)  for  the  Albino,  the  rate  of 
increase  is  apparently  ten  times  as  great  in  the  Norway  as  in 
the  Albino.  This  will  be  discussed  later. 

The  nucleus-plasma  relation 

In  determining  the  increase  in  volume  of  the  cytoplasm  in 
relation  to  that  of  the  nucleus,  the  computed  diameters  of  the 

TABLE  9 


Giving  the  average  diameters  of  the  cells  and  nuclei  according  to  body  weight.  The 
nucleus -plasma  ratios  based  on  these  diabieters  are  given  in  the  last  column. 
Data  condensed.  Superior  cervical  sympathetic  ganglion.  Norway  rat 


NUMBER  OF 
CASES 

BODY  WEIGHT 
RANGE 

MEAN 

BODY 

WEIGHT 

t 

DIAMETERS 

NUCLEUS-PLASMA 

RATIOS 

Cell 

Nucleus 

grams 

U 

U 

16 

6-  38 

22.2 

22.3 

12.1 

1  :  5.3 

16 

41-100 

65.9 

25.0 

12.8 

1  :  6.4 

8 

104-150 

121.4 

26.8 

13.0 

1  :  7.7 

16 

152-195 

175.4 

27.9 

13.1 

1  :  8.6 

16 

206-250 

226.6 

30.1 

13.5 

1  : 10.0 

5 

259-290 

270.1 

32.7 

13.7 

1  :  12.4 

8 

311-402 

346.1 

32.2 

13.8 

1  :  11.6 

cell  and  of  the  nucleus  have  been  condensed  according  to  body 
weight  and  arranged  in  table  9.  By  subtracting  the  volume 
of  the  nucleus  from  that  of  the  cell,  the  volume  of  the  cytoplasm 
is  obtained,  and  the  ratios  between  the  latter  and  the  volume 
of  the  nucleus  are  given  in  the  last  column  of  table  9.  This 
table  shows  that  the  increase  of  the  cytoplasm  is  progressive, 
except  in  the  last  group. 

In  general  it  may  be  said  that  for  each  50  grams  of  increase 
in  body  weight,  the  increase  in  the  ratio  is  one  unit.  For  a 
body  weight  of  22.2  grams  (about  twenty-five  days  of  age) 
the  ratio  is  about' one-half  that  for  the  oldest  group  with  a  body 


328 


CHI  PING 


weight  of  346  grams.  As  compared  with  ratios  for  standard 
Albinos  of  like  body  weights  (table  2 ,  Ping  ’21),  the  ratios 
for  the  Norway  are  clearly  low. 


DISCUSSION 


In  the  foregoing  paragraphs  the  growth  of  the  cells  in  the 
Norway  rat  has  been  treated  in  relation  to  the  body  weight 
and  length  and  in  relation  to  age,  either  observed  or  inferred 
from  the  percentage  of  water  in  the  brain  of  the  animal.  In 
each  case  the  results  show  that  the  growth  is  comparatively 
rapid  at  first  and  then  becomes  gradual.  Moreover,  as  was  to 
be  expected,  the  growth  of  the  sympathetic  nerve  cells  of  the 
Norway  resembles  in  a  general  way  that  of  the  standard  Albino. 
There  are,  however,  differences  between  these  forms,  worthy 
of  note,  and  to  make  the  comparison  as  complete  as  possible, 
the  data  for  the  inbreds  will  also  be  taken  into  consideration. 

Although  the  form  of  these  data  and  the  numbers  of  cases 
are  not  the  same  in  the  three  series,  they  are  yet  sufficiently 
similar  to  make  several  comparisons  worth  while. 

Before  attempting  this,  a  word  about  the  general  relations 
of  the  three  strains  here  examined  is  in  place.  Both  the  Albino 
strains  contained  animals  which  had  been  in  captivity  for  many 
generations,  and  were  also  domesticated  in  the  sense,  that  they 
had  lost  the  fear  of  man  and  were  easy  to  handle.  The  Norway 
strain,  on  the  other  hand,  had  two  groups  in  it:  (1)  the  rats 
caught  wild  and  of  unknown  age — represented  in  this  series  by 
animals  37  grams  or  more  in  body  weight — and  (2)  a  group 
which  were  the  Fi  or  F2  descendants  of  Norway  parents  caught 
wild.  Although  this  second  group  was  composed  of  captive 
individuals,  they  were  by  no  means  domesticated  and  for  the 
most  part  were  still  timid  and  excitable. 

The  differences  between  these  strains  may  be  tabulated  as 
follows: 


Albinos 

Not  pigmented 

Captive 

Domesticated 

(A)  ‘Standard’  (not  inbred) 

(B)  ‘Inbred’ 


Norway  s 
Pigmented 
Wild  or  captive 
Not  domesticated 
Not  inbred 


SYMPATHETIC  CELLS'.  NORWAY  RAT 


329 


By  the  aid  of  such  a  tabulation,  there  seems  to  be  a  chance 
to  consider  the  possible  influence  of  albinism,  captivity,  domes¬ 
tication,  and  inbreeding  on  the  cells  under  discussion. 

The  characters  which  may  be  compared  in  the  several  strains 
are: 

A.  The  morphology  of  the  largest  cells. 

B.  Special  cell  forms  (binuclear,  pigmented,  or  vacuolated). 

C.  The  increase  in  the  diameter  of  the  cells  from  birth  to 
maturity. 

D.  The  absolute  size  of  the  cells  at  different  ages. 

E.  The  nucleus-plasma  ratios. 

F.  The  rate  of  the  formation  of  large  from  small  cells. 

In  making  the  comparison,  the  three  strains  will  be  briefly 
designated  as  ‘standards,’  ‘inbreds,’  and  ‘Norway,’  and  for 
convenience  the  values  for  the  ‘standards’ — which  have  been 
most  completely  studied — will  be  those  to  which  the  values  for 
the  other  strains  are  referred. 

A.  The  morphology  of  the  largest  cells 

Figures  1  to  5  (Ping,  ’21)  show  the  morphology  of  the  largest 
cells  in  the  standards.  In  the  other  strains  these  cells  have  in 
general  a  similar  appearance.  However,  it  was  noted  in  the 
Norway s  that  the  Nissl  granules  were  less  segregated  than  in 
the  standards.  Whether  this  difference  is  correlated  with  albin¬ 
ism  or  domestication  cannot  be  determined  at  present,  because 
the  Norways  have  not  yet  been  domesticated. 

B.  Special  cell  forms 

1.  Binuclear  cells.  In  the  standards,  binuclear  cells  were 
found  in  every  ganglion  examined  (table  5,  Ping,  ’21)  and  the 
average  number  was  4.2  per  ganglion.  In  the  Norway  they 
were  found  in  only  54  out  of  80  ganglia  studied  (table  6).  The 
average  number  for  the  entire  series  of  80  ganglia  was  2.2  per 
ganglion,  and  for  the  54  ganglia  in  which  they  occurred,  3.3.  In 
the  Norways  therefore,  binuclear  cells  are  less  abundant.  Again 
this  difference  cannot  be  correlated  with  either  albinism  or 
domestication. 


330 


CHI  PING 


TABLE  10 

Increase  from  birth  to  maturity.  The  data  for  the  ‘ standards 7  are  Jrom  tabte  1 
{Ping,  ’ 21 )  and  for  the  Norways  from  table  1  of  the  present  paper.  In  each  in¬ 
stance  the  values  are  the  means  for  the  male  and  female  records  at  the  corresponding 
body  weights 


BODY  WEIGHT 

DIAMETERS 

Cell 

Nucleus 

Standards  5.9 

M 

19.7 

fX 

10.8 

178.0 

30.5 

13.5 

Ratios . 

1.54 

1.25 

Percentage  increase . 

55 

25 

Norways  5.8 

16.9 

9.7 

182.0 

27.8 

13.2 

Ratios . 

1.64 

1.36 

Percentage  increase . 

64 

36 

TABLE  11 

Showing ,  in  the  standard  Albino  and  in  the  Norway  rat  at  about  19  grams  and  178 
grams  of  body  weight,  the  diameters  in  u  of  the  largest  cells  and  nuclei  in  the  superior 
cervical  sympathetic  ganglion,  compared  with  those  of  the  cells  from  the  ventral 
horn  of  the  spinal  cord  ( seventh  cervical  segment )  and  from  the  corresponding 
ganglion  ( Donaldson  and  Nagasaka,  ’ 18 ) 


LOCALITY 

STRAIN 

AT  19 

GRAMS 

AT  178 

GRAMS 

Gv1 

Absolute 

LIN 

Percent¬ 

age 

Superior  cervical  sympa- 

thetic  ganglion . 

Standard 

Cells 

24.2 

30.5 

6.3 

26 

Nuclei 

12.1 

13.5 

1.4 

12 

Motor  cells,  spinal  cord. . . . 

Standard 

Cells 

23.9 

29.1 

5.2 

22 

Nuclei 

12.9 

15.1 

2.2 

17 

Spinal  ganglion  cells . 

Standard 

Cells 

21.6 

34.2 

12.6 

58 

Nuclei 

10.6 

16.4 

5.8 

55 

AT  182 

GRAMS 

Superior  cervical  sympa- 

thetic  ganglion . 

Norways 

Cells 

23.0 

27.8 

4.8 

21 

Nuclei 

12.4 

13.2 

0.8 

6 

SYMPATHETIC  CELLS  I  NORWAY  RAT 


331 


2.  Pigmented  cells.  In  the  standards  the  pigmented  cells  do 
not  occur  before  puberty  (table  5 ,  Ping,  ’21);  the  same  is  true 
for  the  Norways  (table  6).  In  the  standards  there  were  found 
about  3.4  pigmented  cells  in  each  of  the  eleven  ganglia  in 
which  such  cells  occurred,  while  in  the  Norways  there  were 
3.8  pigmented  cells  per  ganglion,  after  these  cells  were  first  noted 
at  120  grams  of  body  weight. 

However,  in  one  ganglion  of  the  Norways  eighty-five,  and  in 
another  thirty-seven  pigmented  cells  were  found,  and  it  is  these 
two  cases  which  make  the  average  for  the  Norways  slightly 
above  that  for  the  standards.  This  is  a  surprising  result,  for, 
according  to  common  teaching,  we  should  have  expected  a 
much  greater  number  of  pigmented  cells  in  the  Norways  than 
in  the  standards.  Until  thoroughly  domesticated  Norways 
are  available,  these  relations  cannot  be  interpreted, 

3.  Vacuolated  cells.  These  vacuolated  cells  were  not  found' 
in  the  standards,  but  do  occur  in  the  Norways  after  maturity. 
Their  number  is  small  (table  6).  As  the  data  stand,  the  vacuo¬ 
lated  cells  are  characteristic  for  the  mature  wild  Norways. 

C.  The  increase  in  the  diameters  of  the  cells  from  birth  to  maturity 

As  between  the  standards  and  Norways,  it  is  possible  to  make 
this  comparison  between  birth  and  maturity;  table  10  gives 
what  has  been  found. 

As  the  ratios  and  percentages  show,  the  cells  and  nuclei  have 
increased  a  little  more  in  diameter  in  the  Norway  than  in  the 
standards,  but  this  difference  appears  to  depend  mainly  on 
the  small  size  of  these  cells  at  one  day  of  age  in  the  Norway. 

If  we  choose  the  values  at  about  19  grams  of  body  weight  for 
the  initial  data,  it  is  possible  to  compare  the  changes  in  the 
diameters  of  these  cells,  not  only  in  the  standards  and  Norways, 
but  also  with  those  of  the  cells  in  the  spinal  ganglia  and  ventral 
horn  of  the  spinal  cord,  as  observed  in  the  standard  rats  (Don¬ 
aldson  and  Nagasaka,  T8).  The  relations  appear  in  table  11. 

This  table  11  may  be  used  for  two  purposes.  First,  it  shows 
that  within  the  limits  of  body  weight  chosen  the  percentage 


332 


CHI  PING 


gains  in  these  cells  are  of  the  same  order  in  the  Norways  as  in 
the  standards — 21  per  cent  and  26  per  cent,  respectively,  for 
the  cell  body.  The  two  strains  are  therefore  similar  in  this 
character.  Second,  that  this  order  of  enlargement  is,  on  the 
one  hand,  similar  to  that  found  for  the  large  motor  cells  in  the 
spinal  cord,  and,  on  the  other,  very  different  from  that  found  for 
the  corresponding  spinal  ganglion  cells.  This  later  relation 
indicates  that  the  sympathetic  ganglion  cells,  which  are  efferent 
in  function,  behave  like  motor  cord  cells  during  their  later  growth. 

TABLE  12 

Comparing,  according  to  body  weight,  the  average  diameters  of  the  cells  and  nuclei 
in  the  superior  cervical  sympathetic  ganglion  of  the  Norway  with  that  of  the  stand¬ 
ards.  The  data  for  the  Norway  rat  are  condensed  from  table  2,  and  for  the  Albino 
from  table  2  of  the  former  study  {Ping,  '21).  Sexes  combined 


ALBINO  RAT 

NORWAY  RAT 

Body  weight 

Nucleus 

Cell 

Cell 

Nucleus 

Body  weight 

grams 

M 

P 

U 

grams 

6 

10.8 

19.7 

16.8 

9.7 

6 

15 

13.1 

25.7 

22.6 

12.7 

14 

31 

12.2 

25.0 

23.9 

12.4 

32 

53 

13.2 

27.2 

24.3 

12.7 

51 

73 

13.2 

29.2 

25.8 

13.0 

74 

106 

13.6 

29.8 

25.7 

13.0 

103 

151 

13.2 

28.9 

27.2 

13.3 

157 

178 

13.5 

30.5 

27.2 

13.1 

189 

Average  . . 

12.8 

27.0 

24.2 

12.5 

Percentage  difference  in  cell  diameter  =11  per  cent 
Percentage  difference  in  nucleus  diameter  =  3  per  cent 


D.  Absolute  size  of  cells  at  different  ages 
E.  Nucleus-plasma  ratios 

In  the  first  instance  we  shall  take  up  cell  size  alone  and  limit 
the  comparison  to  that  of  the  Norways  to  the  standards. 

In  table  12  the  mean  diameters  of  the  cells  and  nuclei  of  the 
standards  and  Norways  are  arranged  according  to  their  respective 
body  weights,  the  former  data  being  from  table  2  of  my  previous 
paper,  the  latter  from  the  foregoing  table  2  of  the  present  paper. 


SYMPATHETIC  CELLS:  NORWAY  RAT 


333 


A  study  of  table  12  gives  a  clear  idea  of  the  quantitative  dif¬ 
ference  in  growth  between  these  two  forms,  and  the  same  data 
are  represented  by  graphs  in  chart  5.  From  the  chart  it  is 
evident  that  the  diameters  of  the  cell  body  in  the  Norways  are 
consistently  below  those  in  the  standards. 

The  data  for  these  two  strains  have  been  compared  also  on  body 
length,  on  age,  and  on  the  percentage  of  water  in  the  brain  and 
by  all  of  these  methods  of  comparison  show  relations  essentially 
like  those  just  presented.  Thus,  no  matter  what  the  basis  of 


uiameters  ot  uens  ana  iNucie 

in  micra 

•  O— 

— 

P  — 

o  — 

O" 

— 

-a 

V 

r 

-  4 

h 

f 

i 

& 

D  — 

A** 

$ 

r 

cA— 

- 7 

y 

Body  weight- 

-n  mQ 

0  25  50  75  100  125  150  175  200 

Chart  5.  Based  on  table  12  giving  the  diameters  of  the  cells  and  their  nuclei 


on  body  weight  in  the  Norway  rat  compared  with  the  standard  albino. 

Norway  A  —  A  Albino  0  —  0 

comparison,  these  cells  in  the  Norways  are  smaller  than  those 
in  the  standards. 

In  order  to  compare  with  the  standards  the  inbreds  as  well 
as  the  Norways,  a  series  of  data,  selected  from  the  previous  re¬ 
cords,  have  been  assembled  in  table  13. 

An  examination  of  table  13  brings  to  light  several  interesting 
relations.  While  in  five  out  of  the  six  instances  the  diameters 
of  the  nuclei  are  similar,  there  is  nevertheless  a  great  difference 
in  the  diameters  of  the  cells  according  to  strain.  The  differences 
therefore  appear  mainly  in  the  cytoplasm.  As  compared  with 
the  standards,  the  inbred  cells  are  small,  while  the  cells  of  the 
Norways,  though  also  small,  differ  much  less. 


334 


CHI  PING 


The  smaller  size  of  the  cells  in  the  inbreds  and  Norways  is 
not  related  to  pigmentation,  for  the  inbreds  with  the  smaller 
cells  are  not  pigmented.  It  is  not  due  to  domestication,  for 
both  the  standards  and  inbreds  are  domesticated. 

It  would  appear  therefore  to  be  a  characteristic  of  this  inbred 
strain,  but  without  further  evidence  it  cannot  be  said  to  be  due 
to  inbreeding. 

Since  the  differences  according  to  strain  are  mainly  in  the  cell,, 
the  nucleus-plasma  ratios  show  the  same  relations  as  do  the 
cell  diameters,  and  the  most  striking  feature  is  the  small  value 

TABLE  13 


Giving  the  diameters  and  nucleus -plasma  ratios  of  the  standard ,  inbred  and  Norway 
rats  according  to  body  weight ,  based  on  previous  tables .  In  each  instance  the 
values  given  are  for  the  two  sexes  combined 


STRAIN 

BODY  WEIGHT 

DIAMI 

Cells 

:ters 

Nucleus 

N  UCLE  US-PL  ASM  A 
RATIO 

* 

grams 

M 

M 

Standard . 

145 

28.9 

13.2 

1  :  9.5 

Inbred . 

144 

24.5 

13.2 

1  :  5.4 

Norway . 

146 

28.0 

13.1 

1  :  8.8 

Standard . 

200 

34.1 

14.5 

1  : 12.0 

Inbred . 

206 

25.4 

13.3 

1  :  5.9 

N  orway . 

203 

28.0 

13.1 

1  :  8.8 

for  the  ratios  in  the  inbreds.  The  data  for  the  heavier  body 
weights  show  that  in  this  group  these  cells  in  the  inbreds  have 
only  half  the  volume  of  those  in  the  standards. 

Perhaps  the  point  of  most  general  interest  which  is  thus  brought 
out  is  the  plasticity  or  variability  in  the  size  of  this  group  of 
cells  according  to  strain. 

F .  The  rate  of  the  formation  of  large  from  small  cells 

As  table  6  (Ping,  ’21)  shows,  in  the  standards  the  number  of 
large  and  advanced  cells  increases  about  thirteen-fold  from  one 
to  twenty  days.  On  the  other  hand,  table  8  of  this  paper  indi- 


SYMPATHETIC  CELLS:  NORWAY  RAT 


335 


cates  in  the  Norway  an  increase  during  this  same  interval,  which 
is  about  135-fold,  or  nearly  ten  times  as  large.  One  circumstance 
which  contributes  to  this  result  is  the  lower  standard  which  was 
taken  for  the  large  cells  in  the  Norway,  in  order  to  get  a  reason¬ 
able  number  of  such  cells  at  birth.  The  use  of  this  lower  standard 
gives  of  course  a  higher  number  at  maturity  in  the  Norway. 
This  is,  however,  a  trifling  matter,  and  the  more  important  dif¬ 
ference  between  the  two  strains  lies  in  the  relatively  small  number 
of  large  cells  in  the  Norway  at  one  day  of  age. 

This  is  an  expression  of  retardation  in  the  early  growth  of 
the  Norway  in  captivity — a  peculiarity  which  has  been  noted 
by  several  observers  and  which  has  been  demonstrated  by  Dr. 
Helen  D.  King  for  the  general  body  growth. 

Here  again  it  is  not  possible  to  offer  a  precise  explanation, 
for  this  relative  retardation  may  be  a  character  of  the  Norway 
in  the  wild  state  and  hence  difficult  to  study,  or  it  may  be  a 
response  to  captivity,  as  these  observations  were  made  on  young 
born  in  captivity  from  Norways  not  yet  domesticated. 

It  is  possible,  however,  to  conclude  that  the  retardation  in 
the  early  development  of  these  cells  is  found  in  the  wild  as  con¬ 
trasted  with  the  domesticated  standard  strain. 

To  determine  the  general  significance  of  these  results,  a  brief 
review  of  some  earlier  observations  along  similar  lines  may  be 
of  value. 

In  the  presentation  of  these  the  data  for  the  wild  Norway 
will  be  taken  as  the  standard,  as  this  is  the  strain  from  which 
the  Albino  has  been  derived. 

\ 

As  compared  with  wild  Norways  of  like  body  weights,  the 
standard  Albinos  have  lighter  brains  and  lighter  spinal  cords 
(16  and  12  per  cent,  respectively;  Donaldson  and  Hatai,  Tl). 
Further,  two  portions  of  the  brain,  the  olfactory  bulbs  and  the 
paraflocculi,  are,  relatively,  still  lighter  in  the  Albino. 

As  between  the  sexes  within  the  same  strain,  it  was  found  that 
while  the  weight  of  the  spinal  cord  (on  body  weight)  was  similar 
in  the  two  sexes  in  the  Norways,  yet  in  the  standard  Albinos 
the  weight  of  the  cord  in  the  female  was  relatively  heavier  than 
in  the  male  (Donaldson  and  Hatai,  Ml). 


336 


CHI  PING 


On  comparing  the  diameters  of  the  cells  in  the  cerebral  cortex 
of  the  rat,  Sugita  (’18)  found  that  those  in  the  lamina  pyramidalis 
and  in  the  lamina  ganglionaris  of  the  Albinos  were,  respectively, 
4  and  7  per  cent  less  in  diameter  than  the  corresponding  cells 
in  the  Norway. 

In  the  foregoing  instances  it  appears  that  there  is  a  reduction 
in  the  relative  size  of  the  parts  of  the  nervous  system,  as  well 
as  in  some  of  the  cell  elements,  in  the  Albino  as  compared  with 
Norway. 

Incidental  observations  on  captive  Norways  suggest  that 
this  reduction  is  the  result  of  captivity  or  domestication.  There 
remains,  however,  the  difference  in  the  relative  weights  of  the 
spinal  cord  which  occurs  in  the  Albino,  but  is  absent  in  the 
Norway,  and  in  this  instance  it  is  possible  that  albinism  plays 
a  part.  From  these  earlier  observations  we  should  have  ex¬ 
pected  to  find  the  cells  in  the  superior  cervical  sympathetic 
ganglion  smaller  in  the  Albinos. 

Contrary  to  expectation,  these  cells  in  the  standards  are 
larger  than  in  the  Norway,  but  also  exhibit  a  sex  difference, 
being  larger  in  the  females.  Nevertheless,  in  the  case  of  the 
inbreds,  these  cells  are  much  smaller  than  in  the  Norways,  and 
show  only  a  slight  difference  according  to  sex.  At  the  moment, 
therefore,  the  size  of  these  cells  in  the  standards  does  not  agree 
with  the  expectation  based  on  the  results  obtained  from  other 
parts  of  the  nervous  system,  but  any  simple  interpretation  is 
at  once  precluded  by  the  very  small  size  which  they  have  in  the 
inbreds. 

SUMMARY 

1.  The  growth  of  the  largest  cells  in  the  superior  cervical 
sympathetic  ganglion  of  the  Norway  has  two  phases:  (1)  a  com¬ 
paratively  rapid  growth  from  birth  to  twenty-five  days,  (2) 
followed  by  a  slow  and  gradual  growth  continuing  to  the  end 
of  the  record. 

2.  The  growth  of  these  cells  in  relation  to  body  weight,  body 
length,  age,  and  the  percentage  of  water  in  the  brain  does  not 
show  differences  due  to  sex  after  the  animal  has  passed  puberty. 


SYMPATHETIC  CELLS  I  NORWAY  RAT 


337 


3.  The  morphological  changes  in  the  cells  are  in  general  similar 
to  those  found  in  the  Albino,  but  the  stainable  substance  is 
somewhat  less  aggregated.  The  binuclear  cells  and  the  cells 
with  pigment  are  present,  as  in  the  Albino,  but  the  latter  are 
only  slightly  more  numerous  in  the  Norway.  Besides,  there 
are  in  the  Norway  a  few  vacuolated  cells. 

4.  The  mode  of  growth  of  the  cells,  as  in  the  Albino,  shows 
similarity  to  that  of  the  motor  cells  of  the  spinal  cord. 

5.  The  nucleus-plasma  ratio  is  1  to  5  at  birth  and  1  to  12 
after  maturity. 

6.  The  cells  at  birth  are  about  16  per  cent  less  in  diameter 
than  those  of  the  Albino.  The  growth  acquired  after  the 
weaning  period  is  about  10  per  cent  less  than  that  of  the 
Albino,  such  difference  being  probably  due  to  domestication. 

7.  Comparing  with  the  standard  Albino  the  data  for  the  wild 
Norways,  it  appears  that  in  the  Norways  the  diameters  of  the 
nuclei  are  the  same,  but  those  of  the  cell  bodies  are  slightly 
less.  As  a  consequence,  the  nucleus-plasma  ratios  are  smaller 
in  the  Norway.  Moreover,  there  is  no  clear  sex  difference  in 
the  size  of  these  cells. 

8.  Comparing  the  inbreds  with  the  standard  albinos  in  re¬ 
spect  of  these  cells,  it  appears  that  in  the  inbreds  the  sex  dif¬ 
ference  in  size  is  less  marked.  The  absolute  diameters  of  the 
nuclei  are  similar  to  those  for  the  standards  and  Norwavs,  but 
the  diameters  of  the  cells  are  much  less,  and  in  consequence 
the  nucleus-plasma  ratios  are  only  about  half  those  for  the 
standards. 

9.  The  interpretation  of  these  differences  awaits  the  data 
to  be  obtained  from  Norways  after  long-continued  domestica¬ 
tion  and  inbreeding. 


338 


CHI  PING 


LITERATURE  CITED 

Apolant,  H.  1896  Uber  die  sympathischen  Ganglienzellen  der  Nager.  Arch, 
f.  mikr.  Anat.,  Bd.  47,  S.  461-471. 

Donaldson,  H.  H.  1910  On  the  percentage  of  water  in  the  brain  and  in  the 
spinal  cord  of  the  albino  rat.  Jour.  Neur.  and  Psychol.,  vol.  20,  pp. 
119-144. 

Donaldson,  H.  H.,  and  Hatai,  S.  1911  A  comparison  of  the  Norway  rat  with 
the  albino  rat  in  respect  to  body  length,  brain  weight,  spinal  cord 
weight  and  the  percentage  of  water  in  both  the  brain  and  the  spinal 
cord.  Jour.  Comp.  Neur.,  vol.  21,  pp.  417-458. 

1915  The  Rat.  Reference  tables  and  data  for  the  albino  rat  (Mus 
norvegicus  albinus)  and  the  Norway  rat  (Mus  norvegicus).  Memoirs 
of  The  Wistar  Institute  of  Anatomy  and  Biology,  no.  6. 

1916  A  revision  of  the  percentage  of  water  in  the  brain  and  in  the 
spinal  cord  of  the  albino  rat.  Jour.  Comp.  Neur.,  vol.  27,  pp.  77-115. 

Donaldson,  H.  H.,  and  Nagasaka,  G.  1918  On  the  increase  in  the  diameters 
of  nerve  cell  bodies  and  of  the  fibers  arising  from  them — during  the 
later  phases  of  growth  (albino  rat).  Jour.  Comp.  Neur.,  vol.  29, 
pp.  529-552. 

Gaskell,  W.  H.  1920  The  involuntary  nervous  system.  Longmans,  Green 
&  Co.,  New  York. 

Hatai,  S.  1907  On  the  zoological  position  of  the  albino  rat.  Biol.  Bull., 
vol.  12,  pp.  266-273. 

1914  On  the  weight  of  some  of  the  ductless  glands  of  the  Norway 
and  of  the  albino  rat  according  to  sex  and  variety.  Anat.  Rec.,  vol. 
8,  pp.  511-523. 

Ping,  Chi  1921  On  the  growth  of  the  largest  nerve  cells  in  the  superior  cervical 
sympathetic  ganglion  of  the  albino  rat — from  birth  to  maturity. 
Jour.  Comp.  Neur.,  vol.  33,  no.  3. 

Ramon  y  Cajal,  S.  1911  Histologie  du  systeme  nerveux,  T.  2,  pp.  891-942. 
Stjgita,  N.  1918  Comparative  studies  on  the  growth  of  the  cerebral  cortex. 

VI.  Part  I.  On  the  increase  in  size  and  on  the  developmental  changes 
of  some  nerve  cells  in  the  cerebral  cortex  of  the  albino  rat  during  the 
growth  of  the  brain.  Part  II.  On  the  increase  in  size  of  some  nerve 
cells  in  the  cerebral  cortex  of  the  Norway  rat  (Mus  norvegicus)  com¬ 
pared  with  the  corresponding  changes  in  the  albino  rat.  Jour.  Comp. 
Neur.,  vol.  29,  pp.  119-162. 


